Bacillus

Non-pathogenic Bacillus species used in cleaning products produce the appropriate enzymes to degrade stains and soils. However, there is little scientific data regarding the human exposure by inhalation of Bacillus spores during or after use of microbial-based cleaning products. Herein, air samples were collected at various locations in a ventilated, carpeted, residential room to determine the air concentration of viable bacteria and spores during and after the application of microbial-based carpet cleaning products containing Bacillus spores. The influence of human activities and vacuuming was investigated. Bioaerosol levels associated with use and post-application activities of whole room carpet treatments were elevated during post-application activity, but quickly returned to the indoor background range. Use of trigger spray spot applications generated aerosolized spores in the immediate vicinity, however, their use pattern and the generation of mostly non-respirable particles su...

Global food shortage is mainly due to the post-harvest spoilage of food, rather than its under-production, especially in the sub-Saharan African countries. Rapid detection tools for the spoilage of fruit such as banana (Musa acuminata) would be a great resource in alleviating losses during post-harvest storage. In this study, silver-based colloidal nanoparticle (AgNPs) solution was synthesized using culture supernatant or wet biomass (cell pellets) of Bacillus subtilis. The synthesized silver nanoparticles solution was confirmed using UV-Vis Spectrophotometer and further characterized using Scanning Electron Microscope (SEM), X-ray Diffractometer (XRD) and Fourier Transmission Infrared (FT-IR), and then evaluated as a colorimetric sensor for the volatile compound released during the deterioration of Musa acuminata. The original reddish brown colour of the silver nanoparticle solution changed to light brown by the end of the fourth day and finally turned transparent on the tenth day. Simultaneous analysis carried out by UV-Vis spectroscopy corroborates our investigation of AgNPs as a colorimetric sensor displaying selectivity and specificity for 1,2-Benzenedicarboxylic acid, bis (2-methyl propyl) ester which was released during the deterioration of Musa acuminata. The use of colorimetric sensor as conducted in this study will help in easy detection for control of crop deterioration.

Anaerobic digestion is an appropriate technique for the treatment of sludge before final disposal and it is employed worldwide as the oldest and most important process for sludge stabilization. In general, mesophilic anaerobic digestion of sewage sludge is more widely used compared to thermophilic digestion. Furthermore, thermal pre-treatment is suitable for the improvement of stabilization, enhancement of dewatering of the

Terpenoids are the largest group of small-molecule natural products, with more than 60,000 compounds made from isopentenyl diphosphate (IPP) and its isomer dimethylallyl diphosphate (DMAPP). As the most diverse group of small-molecule natural products, terpenoids play an important role in the pharmaceutical, food, and cosmetic industries. For decades, Escherichia coli (E. coli) and Saccharomyces cerevisiae (S. cerevisiae) were extensively studied to biosynthesize terpenoids, because they are both fully amenable to genetic modifications and have vast molecular resources. On the other hand, our literature survey (20 years) revealed that terpenoids are naturally more widespread in Bacillales. In the mid-1990s, an inherent methylerythritol phosphate (MEP) pathway was discovered in Bacillus subtilis (B. subtilis). Since B. subtilis is a generally recognized as safe (GRAS) organism and has long been used for the industrial production of proteins, attempts to biosynthesize terpenoids in th...

Extreme environments merit special attention and significance because of the possible existence of thermophilic microorganisms in such ecological niches. Keeping this in mind indigenous stove ash samples were explored for extremophilic bacteria in term of their biodiversity. Accordingly, this study reports 37 bacterial isolates from the local wood run oven (Tandoor) ash samples. All the isolated strains belong to genus Bacillus on the bases of morpho-cultural and biochemical considerations. The average temperature tolerance profile was >45°C thereby, indicating towards the thermophilic nature of the isolated strains. The Bacillus isolates were screened for 10 different hydrolytic enzymes (cellulase, xylanase, amylase, pectinase, caseinase, keratinase, lipase, esterase, dextranase and β-galactosidase) by plate screening method using the medium incorporated with specific substrate(s). It was found that keratinase was produced by all the isolates while, 36 (97.2%) isolates showed ca...

ABSTRACTAnalysis of the genome ofBacillus haloduransstrain C125 indicated that two pathways leading from a cytosine deoxyribonucleotide to dUMP, used for dTMP synthesis, were encoded by the genome of the bacterium. The genes that were responsible, thecomEBgene and thedcdBgene, encoding dCMP deaminase and the bifunctional dCTP deaminase:dUTPase (DCD:DUT), respectively, were both shown to be expressed inB. halodurans, and both genes were subject to repression by the nucleosides thymidine and deoxycytidine. The latter nucleoside presumably exerts its repression after deamination by cytidine deaminase. BothcomEBanddcdBwere cloned, overexpressed inEscherichia coli, and purified to homogeneity. Both enzymes were active and displayed the expected regulatory properties: activation by dCTP for dCMP deaminase and dTTP inhibition for both enzymes. Structurally, theB. haloduransenzyme resembled theMycobacterium tuberculosisenzyme the most. An investigation of sequenced genomes from other specie...

Eighty-one bacterial strains isolated from refrigerated raw milk, 124 from pasteurized milk and cream stored at 5 degrees C and 7 degrees C, and 19 type and reference strains of Pseudomonas spp. and Bacillus spp. were characterized by numerical phenotypic analysis. Data were processed with simple matching (SSM) and Jaccard (SJ) coefficients, and UPGMA clustering. Fourteen clusters of Gram-negative bacteria were formed at SJ = 79% (SSM = 90%). Raw milk was exclusively spoilt by Gram-negative bacteria, the majority of which were Pseudomonas fluorescens biovar I, Ps. fragi, Ps. lundensis and Ps. fluorescens biovar III. Minor groups in raw milk included Enterobacteriaceae spp. and Acinetobacter spp. Pasteurized milk was spoilt by essentially the same Gram-negative organisms in 65% (5 degrees C) and 50% (7 degrees C) of the cases. The phenotypic characteristics of Gram-negative bacteria are given. Bacillus polymyxa (both temperatures) and B. cereus (only at 7 degrees C) were responsible for 77% of samples spoiled by the Gram-positive organisms. Minor milk spoilage groups included other Bacillus spp. and lactic acid bacteria. All Bacillus spp. grew fermentatively in milk, and most strains denitrified. It is suggested that: (i) industrial recontamination tests of pasteurized milk are directed against Pseudomonas; (ii) milk is stored at 5 degrees C or lower to avoid growth of B. cereus; and (iii) the significance of gas-producing and nitrate/nitrite-reducing Bacillus strains is recognized in cheese production.

The production of d-ribose by fermentation has received much attention lately, possibly because of the use of this pentose to synthesize antiviral and anticancer drugs. This review briefly outlines the methods that have been used to synthesize d-ribose since it was identified in yeast RNA, and focuses in particular on the latest developments in d-ribose fermentation, which have led to d-ribose yields that exceed 90 g/l. Furthermore, the various transketolase-deficient d-ribose-producing mutants that are used, and the biochemical and genetic rationales applied to select them or to enhance their d-ribose productivities, are dealt with. Attention is also drawn to the unusual pleiotropic characteristics of the mutant strains, as well as to the industrial and academic applications of d-ribose.