American Journal of Agricultural and Biological Science
Biofertilizer is a relatively safer, environmentally friendly and cost-effective approach as an a... more Biofertilizer is a relatively safer, environmentally friendly and cost-effective approach as an alternative to reduce chemical fertilizer usage. The selection of bacterial strains with multiple beneficial characteristics are important to maximize the effectiveness on the host plant. Due to aforementioned interest, several Plant Growth-Promoting Rhizobacterial (PGPR) and rhizobial strains were isolated from rice and legume roots, respectively, at four locations in Malaysia namely Universiti Putra Malaysia (UPM), Serdang, Selangor; Besut, Terengganu; Tunjung, Kelantan and Sik, Kedah. Bacterial isolations were undertaken to select the best isolates which exhibit multiple beneficial effects to the rice plant and a total of 205 bacterial strains were isolated and categorized as follows; 94 rhizospheric and 107 endophytic bacteria from rice roots, one rhizobial strain from soybean and three from Mimosa pudica. These isolates were screened for their abilities to fix N 2 and solubilize phosphate; 52 were positive for both tests. The selected isolates were then tested for IAA production and other biochemical tests such as potassium solubilization, hydrolyzing enzymes (cellulase and pectinase) and iron siderophore productions. Four isolates, namely UPMB19 (rhizospheric PGPR from Tunjung, Kelantan), UPMB20 (endophytic PGPR from Besut, Terengganu), UPMR30 (rhizobia from soybean) and UPMR31 (rhizobia from Mimosa) were selected for subsequent plant inoculation tests with UPMB10, a PGPR isolated from oil palm root, as the reference strain. Based on 16S rDNA gene sequencing, these bacterial strains were identified under several genera: Lysinibacillus, Alcaligenes, Bradyrhizobium, Rhizobium and Bacillus, respectively. Results of plant inoculation test indicated that UPMB19 significantly enhanced the seedling height at the early growth stage (7 days after transplanting, DAT) which could be attributed to the higher N 2 fixation rate of this strain as compared to the other strains, except UPMB20. UPMB10 and UPMR31 also showed significant effects with increased seedling height and Total Dry Weight (TDW) at the later stage (14 DAT) possibly due to the higher bacterial population and IAA produced as observed in the residual nutrient solution without addition of fertilizer-N. This study has successfully demonstrated the effectiveness of locally isolated PGPR and rhizobial strains with multiple beneficial characteristics on early growth and vigor of rice seedlings under controlled condition. The result proved to be a vital information in the development of a liquid biofertilizer for rice; thus further studies will be done to evaluate the effectiveness of these isolates under glasshouse and field conditions on growth, tillering and yield of rice.
Banana, an important fruit crop, requires high amounts of chemical fertilizers for commercial cul... more Banana, an important fruit crop, requires high amounts of chemical fertilizers for commercial cultivation, which is costly and can be hazardous to the environment, when used excessively. Plant growth promoting rhizobacteria (PGPR) could be used for growth promotion, nutrient uptake and some time as an alternative source of N-fertilizer of non-leguminous crops. Recently, research on PGPR for crop improvements are gaining prominence and thousands of research works have been published so far. However, use of this noble technique in banana production system is limited. Nevertheless, reports from various experimental findings suggested that PGPR strains could successfully formed colonies on the root surface of bananas, where more bacterial cells were found in the root hair proliferation zone. Application of PGPR alone could not produce significant benefits that require minimal or reduced levels of fertilizer-N consequently could produce a synergistic effect on root growth and development...
Epidemiology of melioidosis is poorly understood because its occurrence is influenced by complex ... more Epidemiology of melioidosis is poorly understood because its occurrence is influenced by complex interaction of environmental, climatic, physicochemical and host factors. We investigated the potential risk factors for exposure to Burkholderia pseudomallei in small ruminants farms in Peninsular Malaysia. Melioidosis-positive (n=33) and negative (n=27) farms were selected and visited for interviews and environmental samples collection. The characteristics and putative disease risk factors were compared between the case and the control farms using Chi-square test and logistic regression analysis. The multivariable logistic regression analysis showed that the odds of melioidosis were significantly higher in farms that had bush clearing around farms (odds ratio [OR]=6.61, 95% confidence interval [CI]=1.12-38.84, p=0.037), in farms with B. pseudomallei present in the soil (OR=6.23, 95%CI=1.03-37.68, p=0.046), in farms that have other animal species present (OR=7.96, 95%CI=1.14-55.99, p=0.037) and in farms that had flooding or waterlogging conditions (OR=11.95, 95%CI=1.39-102.6, p=0.024) when compared to the odds of the disease in farms that did not have the above conditions. The odds of the disease in farms that treated their soils with lime were significantly lower (OR=0.028, 95%CI=0.003-0.29, p=0.003) compared to the odds in those that did not. The risk factors for exposure to B. pseudomallei highlighted above may have contributed to the occurrence of melioidosis in animals in the study farms. Information from the study may be helpful in planning control measures against melioidosis and have improved understanding of the epidemiology of the disease in livestock farms. This article is protected by copyright. All rights reserved.
Abstract An experiment was conducted at the Soil Microbiology Laboratory, Department of Land Mana... more Abstract An experiment was conducted at the Soil Microbiology Laboratory, Department of Land Management, University Putra Malaysia, Malaysia to observe the effect of plant growth promoting bacterial inoculation on the enhancement of germination and vigor seedling ...
A study was conducted in in vitro condition to determine the specific growth rate, sugar consumpt... more A study was conducted in in vitro condition to determine the specific growth rate, sugar consumption and generation time of four diazotrophic bacterial species, Burkholderia, Rhizobium and two Corynebacterium sp. in four different carbon substrates. Growth of all ...
ABSTRACT An experiment was conducted in undrained poly bags under glasshouse conditions to quanti... more ABSTRACT An experiment was conducted in undrained poly bags under glasshouse conditions to quantify the N2 fixing capacity (15N isotope dilution method) of plant growth promoting rhizobacteria ( Azospirillum and Bacillus spp.) in association with oil palm seedlings. Effects of inoculation on nutrient uptake and plant growth promotion will also be observed. The experiment was arranged in a randomized complete block design with five replications and harvested at 390 days after planting. The treatments involved were: 1) killed Azospirillum brasilense (Sp 7), 2) killed Sp 7; + inorganic-Ni, 3) Sp 7, 4) A. lipoferum (CCM 3863), 5) locally isolated rhizobacteria UPMB 10, and 6) UPMB 13 inoculation. Results showed that inoculation of the rhizobacteria could contribute up to 20-50% of the total nitrogen requirement of the host plant through N2 fixation process. Besides that, the inoculation process had also stimulated accumulation of nutrient and plant growth (tops and roots) comparable to the control with full inorganic nitrogen (Ni) fertilization after 390 days of growth.
Page 1. Acta Biol Malays 1(1): 41-45 http://dx.doi.org/10.7593/abm/1.1.41 Enhancement of Plant Nu... more Page 1. Acta Biol Malays 1(1): 41-45 http://dx.doi.org/10.7593/abm/1.1.41 Enhancement of Plant Nutrient Contents in Rice Straw Vermicompost through the Addition of Rock Phosphate Yan Yi Wei • Nor Azwady Abd. Aziz • Zulkifli ...
A bioflocculant-producing bacterial strain with highly mucoid and ropy colony morphological chara... more A bioflocculant-producing bacterial strain with highly mucoid and ropy colony morphological characteristics identified as Bacillus spp. UPMB13 was found to be a potential bioflocculant-producing bacterium. The effect of cation dependency, pH tolerance and dosage requirement on flocculating ability of the strain was determined by flocculation assay with kaolin as the suspended particle. The flocculating activity was measured as optical density and by flocs formation. A synergistic effect was observed with the addition of monovalent and divalent cations, namely, Na⁺, Ca²⁺, and Mg²⁺, while Fe²⁺ and Al³⁺ produced inhibiting effects on flocculating activity. Divalent cations were conclusively demonstrated as the best cation source to enhance flocculation. The bioflocculant works in a wide pH range, from 4.0 to 8.0 with significantly different performances (P < 0.05), respectively. It best performs at pH 5.0 and pH 6.0 with flocculating performance of above 90%. A much lower or higher ...
There are increasing applications of diazotrophic rhizobacteria in the sustainable agriculture sy... more There are increasing applications of diazotrophic rhizobacteria in the sustainable agriculture system. A field experiment on young immature oil palm was conducted to quantify the uptake of N derived from N₂ fixation by the diazotroph Bacillus sphaericus strain UPMB-10, using the ¹⁵N isotope dilution method. Eight months after ¹⁵N application, young immature oil palms that received 67% of standard N fertilizer application together with B. sphaericus inoculation had significantly lower ¹⁵N enrichment than uninoculated palms that received similar N fertilizers. The dilution of labeled N served as a marker for the occurrence of biological N₂ fixation. The proportion of N uptake that was derived from the atmosphere was estimated as 63% on the whole plant basis. The inoculation process increased the N and dry matter yields of the palm leaflets and rachis significantly. Field planting of young, immature oil palm in soil inoculated with B. sphaericus UPMB-10 might mitigate inorganic fertilizer-N application through supplementation by biological nitrogen fixation. This could be a new and important source of nitrogen biofertilizer in the early phase of oil palm cultivation in the field.
The potential enhancement of root growth and nodulation in vegetable soybean (AGS190) was studied... more The potential enhancement of root growth and nodulation in vegetable soybean (AGS190) was studied with application of Azospirillum brasilense (Sp7) and A. lipoferum (CCM3863) co-inoculated with two Bradyrhizobium japonicum strains (TAL102 and UPMR48). Signi®cant root growth stimulation and nodulation were observed in Azospirillum as well as during its co-inoculation with Bradyrhizobium. Nodule formation is linked with the initiation of new roots; nodules were almost absent even in Bradyrhizobium inoculated plant due to the absence of new roots development in clipped rooted seedlings. Total root length, root number, speci®c root length, root dry matter, root hair development and shoot dry matter were signi®cantly increased by Azospirillum alone and its co-inoculum. Co-inoculated plants signi®cantly in¯uenced the number of nodules and its fresh weight. A. brasilense seemed to perform better in root growth and nodule development compared to A. lipoferum. q
... MA Baset Mia a , Corresponding Author Contact Information , E-mail The Corresponding Author ,... more ... MA Baset Mia a , Corresponding Author Contact Information , E-mail The Corresponding Author , ZH Shamsuddin b , Z. Wahab c and M ... maize and 40% of the N requirement for oil palm seedlings through biological nitrogen fixation (BNF) under glasshouse condition ([Amir et al ...
This study examined the potential of Pseudomonas aeruginosa abundance in the intestines of fish a... more This study examined the potential of Pseudomonas aeruginosa abundance in the intestines of fish as an indicator of exposure to benzo[a]pyrene (BaP). P. aeruginosa populations were enumerated in juvenile African catfish (Clarias gariepinus) injected intramuscularly three days previous with 0, 10, 30, 40, 50 or 70mg/kg of BaP. Hepatic EROD and GST activities and biliary fluorescent aromatic compounds (FACs) 1-OH BaP, 3-OH BaP, 7,8-D BaP and BaP were quantified to investigate agreements between the new indicator and established fish biomarkers. The shape of bacterial population (logarithm of colony-forming unit) dose-response curve generally matched those of biliary FACs concentrations. Conversely, the EROD and GST dose-response curves were generally the mirror images of the bacterial population curve. Changes in intestinal P. aeruginosa population appear to be an indirect effect of BaP exposure because exposure to 0-100μg/ml BaP had no effect on P. aeruginosa populations grown on agar plates containing BaP. Using intestinal P. aeruginosa population of fish as a universal indicator of BaP pollution in aquatic environments is discussed.Conversely, the EROD and GST dose-response curves were generally the mirror images of the bacterial population curve.
High-yielding and quality banana production through plant growth-promoting rhizobacterial (PGPR) ... more High-yielding and quality banana production through plant growth-promoting rhizobacterial (PGPR) inoculation. Abstract Introduction. Rhizobacterial inoculation in low fertilizer-N conditions, viz., 33% fer-tilizer-N of the total N requirement, could produce similar plant ...
Communications in Soil Science and Plant Analysis, 2005
Abstract Plant growth promoting rhizobacteria (PGPR)(eg, Azospirillum and Bacillus spp.) have bee... more Abstract Plant growth promoting rhizobacteria (PGPR)(eg, Azospirillum and Bacillus spp.) have been reported to enhance growth and fix N2 with several nonleguminous crops. These rhizobacteria have the potential to be applied to oil palm seedlings and, consequently, ...
Communications in Soil Science and Plant Analysis, 2001
Stimulation of root growth and promotion of nodulation in vegetable soybean (Glycine max ) by Azo... more Stimulation of root growth and promotion of nodulation in vegetable soybean (Glycine max ) by Azospirillum brasilense was studied under lightroom conditions to understand the possible mechanism of root growth as well as the enhancement of nodule initiation when co-inoculated with Bradyrhizobium. Root growth stimulation of vegetable soybean was positively influenced by the cell-free supernatant of Azospirillum brasilense Sp7 as well as Sp7 itself, and by indole acetic acid (IAA) application. The cell-free supernatant of Sp7 treated plants produced the highest number of roots and root length plant 21 followed by bacterial cells of Sp7 2177 ORDER REPRINTS and IAA log 10 9 M) application. Control plants were the lowest. The cell-free supernatant of Sp7 may contain growth stimulants similar to IAA, which was responsible for enhanced root growth. Nitrite and nitrate did not show positive role in increasing root growth in vegetable soybean. Co-inoculation of Azospirillum with Bradyrhizobium significantly ðP , 0:05Þ promoted nodulation in vegetable soybean. Bradyrhizobium strain UPMR48 performed superior role on promotion of nodule growth by co-inoculation to the strain TAL102. Azospirillum has the potential as a coinoculant with Bradyrhizobium in vegetable soybean cultivation.
Root exudates play an important role in microbial colonization of the rhizosphere. An in vitro ex... more Root exudates play an important role in microbial colonization of the rhizosphere. An in vitro experiment was conducted to study the root exudate sugars and production of amino acids of three different rice (Oryza sativa) genotypes, as well as the influence of these compounds on Rhizobium sp. (Sb16) and Corynebacterium sp. (Sb26) colonization. Using HPLC, a total of 7 carbohydrate sugars and 16 amino acids were identified from the Mahsuri, Mayang Segumpal and MR219 rice root exudates. A significant (p<0.05) relationship was observed between diazotrophic population growth and root exudates sugar and amino acid consumption of the three rice varieties. Higher bacterial population was found in the plant rhizosphere, as compared to the endosphere. Rhizobium sp. consumed more sugar and produced higher rhizosphere population as compared to Corynebacterium sp. The Rhizobium sp. consumed 100% of mannose, xylose, arabinose and sucrose in the root exudates of three rice genotypes. The differences in sugar consumption by Corynebacterium sp. were observed between the rice varieties. Corynebacterium sp. consumed 100% mannose, xylose and fructose in Mahsuri rice, 100% xylose and arabinose in Mayang Segumpal and 100% arabinose and sucrose in MR219 variety. The identification of the preferred carbon sources by the diazotrophs and the selection of genotypes which produce these compounds may increase the root colonization and subsequently N fixation in the rice plants.
American Journal of Agricultural and Biological Science
Biofertilizer is a relatively safer, environmentally friendly and cost-effective approach as an a... more Biofertilizer is a relatively safer, environmentally friendly and cost-effective approach as an alternative to reduce chemical fertilizer usage. The selection of bacterial strains with multiple beneficial characteristics are important to maximize the effectiveness on the host plant. Due to aforementioned interest, several Plant Growth-Promoting Rhizobacterial (PGPR) and rhizobial strains were isolated from rice and legume roots, respectively, at four locations in Malaysia namely Universiti Putra Malaysia (UPM), Serdang, Selangor; Besut, Terengganu; Tunjung, Kelantan and Sik, Kedah. Bacterial isolations were undertaken to select the best isolates which exhibit multiple beneficial effects to the rice plant and a total of 205 bacterial strains were isolated and categorized as follows; 94 rhizospheric and 107 endophytic bacteria from rice roots, one rhizobial strain from soybean and three from Mimosa pudica. These isolates were screened for their abilities to fix N 2 and solubilize phosphate; 52 were positive for both tests. The selected isolates were then tested for IAA production and other biochemical tests such as potassium solubilization, hydrolyzing enzymes (cellulase and pectinase) and iron siderophore productions. Four isolates, namely UPMB19 (rhizospheric PGPR from Tunjung, Kelantan), UPMB20 (endophytic PGPR from Besut, Terengganu), UPMR30 (rhizobia from soybean) and UPMR31 (rhizobia from Mimosa) were selected for subsequent plant inoculation tests with UPMB10, a PGPR isolated from oil palm root, as the reference strain. Based on 16S rDNA gene sequencing, these bacterial strains were identified under several genera: Lysinibacillus, Alcaligenes, Bradyrhizobium, Rhizobium and Bacillus, respectively. Results of plant inoculation test indicated that UPMB19 significantly enhanced the seedling height at the early growth stage (7 days after transplanting, DAT) which could be attributed to the higher N 2 fixation rate of this strain as compared to the other strains, except UPMB20. UPMB10 and UPMR31 also showed significant effects with increased seedling height and Total Dry Weight (TDW) at the later stage (14 DAT) possibly due to the higher bacterial population and IAA produced as observed in the residual nutrient solution without addition of fertilizer-N. This study has successfully demonstrated the effectiveness of locally isolated PGPR and rhizobial strains with multiple beneficial characteristics on early growth and vigor of rice seedlings under controlled condition. The result proved to be a vital information in the development of a liquid biofertilizer for rice; thus further studies will be done to evaluate the effectiveness of these isolates under glasshouse and field conditions on growth, tillering and yield of rice.
Banana, an important fruit crop, requires high amounts of chemical fertilizers for commercial cul... more Banana, an important fruit crop, requires high amounts of chemical fertilizers for commercial cultivation, which is costly and can be hazardous to the environment, when used excessively. Plant growth promoting rhizobacteria (PGPR) could be used for growth promotion, nutrient uptake and some time as an alternative source of N-fertilizer of non-leguminous crops. Recently, research on PGPR for crop improvements are gaining prominence and thousands of research works have been published so far. However, use of this noble technique in banana production system is limited. Nevertheless, reports from various experimental findings suggested that PGPR strains could successfully formed colonies on the root surface of bananas, where more bacterial cells were found in the root hair proliferation zone. Application of PGPR alone could not produce significant benefits that require minimal or reduced levels of fertilizer-N consequently could produce a synergistic effect on root growth and development...
Epidemiology of melioidosis is poorly understood because its occurrence is influenced by complex ... more Epidemiology of melioidosis is poorly understood because its occurrence is influenced by complex interaction of environmental, climatic, physicochemical and host factors. We investigated the potential risk factors for exposure to Burkholderia pseudomallei in small ruminants farms in Peninsular Malaysia. Melioidosis-positive (n=33) and negative (n=27) farms were selected and visited for interviews and environmental samples collection. The characteristics and putative disease risk factors were compared between the case and the control farms using Chi-square test and logistic regression analysis. The multivariable logistic regression analysis showed that the odds of melioidosis were significantly higher in farms that had bush clearing around farms (odds ratio [OR]=6.61, 95% confidence interval [CI]=1.12-38.84, p=0.037), in farms with B. pseudomallei present in the soil (OR=6.23, 95%CI=1.03-37.68, p=0.046), in farms that have other animal species present (OR=7.96, 95%CI=1.14-55.99, p=0.037) and in farms that had flooding or waterlogging conditions (OR=11.95, 95%CI=1.39-102.6, p=0.024) when compared to the odds of the disease in farms that did not have the above conditions. The odds of the disease in farms that treated their soils with lime were significantly lower (OR=0.028, 95%CI=0.003-0.29, p=0.003) compared to the odds in those that did not. The risk factors for exposure to B. pseudomallei highlighted above may have contributed to the occurrence of melioidosis in animals in the study farms. Information from the study may be helpful in planning control measures against melioidosis and have improved understanding of the epidemiology of the disease in livestock farms. This article is protected by copyright. All rights reserved.
Abstract An experiment was conducted at the Soil Microbiology Laboratory, Department of Land Mana... more Abstract An experiment was conducted at the Soil Microbiology Laboratory, Department of Land Management, University Putra Malaysia, Malaysia to observe the effect of plant growth promoting bacterial inoculation on the enhancement of germination and vigor seedling ...
A study was conducted in in vitro condition to determine the specific growth rate, sugar consumpt... more A study was conducted in in vitro condition to determine the specific growth rate, sugar consumption and generation time of four diazotrophic bacterial species, Burkholderia, Rhizobium and two Corynebacterium sp. in four different carbon substrates. Growth of all ...
ABSTRACT An experiment was conducted in undrained poly bags under glasshouse conditions to quanti... more ABSTRACT An experiment was conducted in undrained poly bags under glasshouse conditions to quantify the N2 fixing capacity (15N isotope dilution method) of plant growth promoting rhizobacteria ( Azospirillum and Bacillus spp.) in association with oil palm seedlings. Effects of inoculation on nutrient uptake and plant growth promotion will also be observed. The experiment was arranged in a randomized complete block design with five replications and harvested at 390 days after planting. The treatments involved were: 1) killed Azospirillum brasilense (Sp 7), 2) killed Sp 7; + inorganic-Ni, 3) Sp 7, 4) A. lipoferum (CCM 3863), 5) locally isolated rhizobacteria UPMB 10, and 6) UPMB 13 inoculation. Results showed that inoculation of the rhizobacteria could contribute up to 20-50% of the total nitrogen requirement of the host plant through N2 fixation process. Besides that, the inoculation process had also stimulated accumulation of nutrient and plant growth (tops and roots) comparable to the control with full inorganic nitrogen (Ni) fertilization after 390 days of growth.
Page 1. Acta Biol Malays 1(1): 41-45 http://dx.doi.org/10.7593/abm/1.1.41 Enhancement of Plant Nu... more Page 1. Acta Biol Malays 1(1): 41-45 http://dx.doi.org/10.7593/abm/1.1.41 Enhancement of Plant Nutrient Contents in Rice Straw Vermicompost through the Addition of Rock Phosphate Yan Yi Wei • Nor Azwady Abd. Aziz • Zulkifli ...
A bioflocculant-producing bacterial strain with highly mucoid and ropy colony morphological chara... more A bioflocculant-producing bacterial strain with highly mucoid and ropy colony morphological characteristics identified as Bacillus spp. UPMB13 was found to be a potential bioflocculant-producing bacterium. The effect of cation dependency, pH tolerance and dosage requirement on flocculating ability of the strain was determined by flocculation assay with kaolin as the suspended particle. The flocculating activity was measured as optical density and by flocs formation. A synergistic effect was observed with the addition of monovalent and divalent cations, namely, Na⁺, Ca²⁺, and Mg²⁺, while Fe²⁺ and Al³⁺ produced inhibiting effects on flocculating activity. Divalent cations were conclusively demonstrated as the best cation source to enhance flocculation. The bioflocculant works in a wide pH range, from 4.0 to 8.0 with significantly different performances (P < 0.05), respectively. It best performs at pH 5.0 and pH 6.0 with flocculating performance of above 90%. A much lower or higher ...
There are increasing applications of diazotrophic rhizobacteria in the sustainable agriculture sy... more There are increasing applications of diazotrophic rhizobacteria in the sustainable agriculture system. A field experiment on young immature oil palm was conducted to quantify the uptake of N derived from N₂ fixation by the diazotroph Bacillus sphaericus strain UPMB-10, using the ¹⁵N isotope dilution method. Eight months after ¹⁵N application, young immature oil palms that received 67% of standard N fertilizer application together with B. sphaericus inoculation had significantly lower ¹⁵N enrichment than uninoculated palms that received similar N fertilizers. The dilution of labeled N served as a marker for the occurrence of biological N₂ fixation. The proportion of N uptake that was derived from the atmosphere was estimated as 63% on the whole plant basis. The inoculation process increased the N and dry matter yields of the palm leaflets and rachis significantly. Field planting of young, immature oil palm in soil inoculated with B. sphaericus UPMB-10 might mitigate inorganic fertilizer-N application through supplementation by biological nitrogen fixation. This could be a new and important source of nitrogen biofertilizer in the early phase of oil palm cultivation in the field.
The potential enhancement of root growth and nodulation in vegetable soybean (AGS190) was studied... more The potential enhancement of root growth and nodulation in vegetable soybean (AGS190) was studied with application of Azospirillum brasilense (Sp7) and A. lipoferum (CCM3863) co-inoculated with two Bradyrhizobium japonicum strains (TAL102 and UPMR48). Signi®cant root growth stimulation and nodulation were observed in Azospirillum as well as during its co-inoculation with Bradyrhizobium. Nodule formation is linked with the initiation of new roots; nodules were almost absent even in Bradyrhizobium inoculated plant due to the absence of new roots development in clipped rooted seedlings. Total root length, root number, speci®c root length, root dry matter, root hair development and shoot dry matter were signi®cantly increased by Azospirillum alone and its co-inoculum. Co-inoculated plants signi®cantly in¯uenced the number of nodules and its fresh weight. A. brasilense seemed to perform better in root growth and nodule development compared to A. lipoferum. q
... MA Baset Mia a , Corresponding Author Contact Information , E-mail The Corresponding Author ,... more ... MA Baset Mia a , Corresponding Author Contact Information , E-mail The Corresponding Author , ZH Shamsuddin b , Z. Wahab c and M ... maize and 40% of the N requirement for oil palm seedlings through biological nitrogen fixation (BNF) under glasshouse condition ([Amir et al ...
This study examined the potential of Pseudomonas aeruginosa abundance in the intestines of fish a... more This study examined the potential of Pseudomonas aeruginosa abundance in the intestines of fish as an indicator of exposure to benzo[a]pyrene (BaP). P. aeruginosa populations were enumerated in juvenile African catfish (Clarias gariepinus) injected intramuscularly three days previous with 0, 10, 30, 40, 50 or 70mg/kg of BaP. Hepatic EROD and GST activities and biliary fluorescent aromatic compounds (FACs) 1-OH BaP, 3-OH BaP, 7,8-D BaP and BaP were quantified to investigate agreements between the new indicator and established fish biomarkers. The shape of bacterial population (logarithm of colony-forming unit) dose-response curve generally matched those of biliary FACs concentrations. Conversely, the EROD and GST dose-response curves were generally the mirror images of the bacterial population curve. Changes in intestinal P. aeruginosa population appear to be an indirect effect of BaP exposure because exposure to 0-100μg/ml BaP had no effect on P. aeruginosa populations grown on agar plates containing BaP. Using intestinal P. aeruginosa population of fish as a universal indicator of BaP pollution in aquatic environments is discussed.Conversely, the EROD and GST dose-response curves were generally the mirror images of the bacterial population curve.
High-yielding and quality banana production through plant growth-promoting rhizobacterial (PGPR) ... more High-yielding and quality banana production through plant growth-promoting rhizobacterial (PGPR) inoculation. Abstract Introduction. Rhizobacterial inoculation in low fertilizer-N conditions, viz., 33% fer-tilizer-N of the total N requirement, could produce similar plant ...
Communications in Soil Science and Plant Analysis, 2005
Abstract Plant growth promoting rhizobacteria (PGPR)(eg, Azospirillum and Bacillus spp.) have bee... more Abstract Plant growth promoting rhizobacteria (PGPR)(eg, Azospirillum and Bacillus spp.) have been reported to enhance growth and fix N2 with several nonleguminous crops. These rhizobacteria have the potential to be applied to oil palm seedlings and, consequently, ...
Communications in Soil Science and Plant Analysis, 2001
Stimulation of root growth and promotion of nodulation in vegetable soybean (Glycine max ) by Azo... more Stimulation of root growth and promotion of nodulation in vegetable soybean (Glycine max ) by Azospirillum brasilense was studied under lightroom conditions to understand the possible mechanism of root growth as well as the enhancement of nodule initiation when co-inoculated with Bradyrhizobium. Root growth stimulation of vegetable soybean was positively influenced by the cell-free supernatant of Azospirillum brasilense Sp7 as well as Sp7 itself, and by indole acetic acid (IAA) application. The cell-free supernatant of Sp7 treated plants produced the highest number of roots and root length plant 21 followed by bacterial cells of Sp7 2177 ORDER REPRINTS and IAA log 10 9 M) application. Control plants were the lowest. The cell-free supernatant of Sp7 may contain growth stimulants similar to IAA, which was responsible for enhanced root growth. Nitrite and nitrate did not show positive role in increasing root growth in vegetable soybean. Co-inoculation of Azospirillum with Bradyrhizobium significantly ðP , 0:05Þ promoted nodulation in vegetable soybean. Bradyrhizobium strain UPMR48 performed superior role on promotion of nodule growth by co-inoculation to the strain TAL102. Azospirillum has the potential as a coinoculant with Bradyrhizobium in vegetable soybean cultivation.
Root exudates play an important role in microbial colonization of the rhizosphere. An in vitro ex... more Root exudates play an important role in microbial colonization of the rhizosphere. An in vitro experiment was conducted to study the root exudate sugars and production of amino acids of three different rice (Oryza sativa) genotypes, as well as the influence of these compounds on Rhizobium sp. (Sb16) and Corynebacterium sp. (Sb26) colonization. Using HPLC, a total of 7 carbohydrate sugars and 16 amino acids were identified from the Mahsuri, Mayang Segumpal and MR219 rice root exudates. A significant (p<0.05) relationship was observed between diazotrophic population growth and root exudates sugar and amino acid consumption of the three rice varieties. Higher bacterial population was found in the plant rhizosphere, as compared to the endosphere. Rhizobium sp. consumed more sugar and produced higher rhizosphere population as compared to Corynebacterium sp. The Rhizobium sp. consumed 100% of mannose, xylose, arabinose and sucrose in the root exudates of three rice genotypes. The differences in sugar consumption by Corynebacterium sp. were observed between the rice varieties. Corynebacterium sp. consumed 100% mannose, xylose and fructose in Mahsuri rice, 100% xylose and arabinose in Mayang Segumpal and 100% arabinose and sucrose in MR219 variety. The identification of the preferred carbon sources by the diazotrophs and the selection of genotypes which produce these compounds may increase the root colonization and subsequently N fixation in the rice plants.
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Papers by Zulkifli Shamsuddin