Many tropical pastures are very low in sodium (Playne 1970) yet few experiments have shown respon... more Many tropical pastures are very low in sodium (Playne 1970) yet few experiments have shown responses which could be attributed to supplemen-tation of cattle with this element. Recently Murphy and Plasto (1973) have reported an unequivocal growth response to sodium chloride supplemen-tation of grazing beef cows and their calves. This study reports the growth responses and saliva sodium levels for a group of four 2 year old Droughtmaster 'steers (group 1) grazing blue grass (Bothriochloa decipiens var. Cloncurriensis) dominant pastures known to be low in sodium (0.012%). These are compared with results for a further nine Droughtmaster steers (groups 2 and 3) grazing spear grass (Heteropogon contortus).in combination with Townsville stylo (Stylosanthes humilis) which contained 0.046 % and 0.112 % sodium respectively. Five ani-mals from the spear grass pasture (group 2) were then introduced to the blue grass pasture on 13.xii.74 and measurements of live weight and saliva sodium.mad...
Two ways are explored of using as fuels, the considerable amounts of lignocellulosic materials av... more Two ways are explored of using as fuels, the considerable amounts of lignocellulosic materials available in Australia. Fermentation of lignocellulose by mixed cultures of bacteria to yield volatile fatty acids is discussed, together with separation of the acids from the aqueous fermentation liquor and their conversion to ketones. Ketones and their derivatives are compared with alcohols and ethers in terms of their value as fuels or fuel additives. Cost analysis indicates that the process could be competitive with other proposed processes for obtaining alternative liquid fuels. Gasification and pyrolysis of biomass is reviewed. An opportunity now exists for producing low energy gas from biomass for use in close coupled boilers, furnaces and kilns in place of lpg or liquid petroleum fuels. Despite much progress towards commercial plants, it will be some time before new technology based on catalysed gasifiers and very fast pyrolysis will be economically competitive in Australia (a). Th...
Biotechnology and genetic engineering are defined and their applications in the dairy industry de... more Biotechnology and genetic engineering are defined and their applications in the dairy industry described for pasture and animal improvement, and for dairy product processing in the factory. Problems in establishing new biotechnologies in the dairy industry and the regulatory hurdles that have to be overcome are discussed. Gene probes and monoclonal antibodies as diagnostics, bovine somatotropin to increase milk production, recombinant DNA-rennin in cheesemaking, recombinant-DNA starter cultures, and enzymes to convert lactose to oligosaccharides are used as examples relevant to the dairy industry. It is advocated that the dairy industry develop a biotechnology policy and an education programme, and actively consider joint ventures with dedicated biotechnology companies.
The investigation of various media formulations, using pure cultures and commercial yogurts, prov... more The investigation of various media formulations, using pure cultures and commercial yogurts, provided the basis for selecting suitable methods to enumerate probiotic cultures. Full and reduced-fat yogurts from four manufacturers of commercial probiotic yogurts were sampled one day post manufacture and analysed for constitutive microflora. Samples were stored at 4°C and 10°c, with subsequent sampling and testing at approximately two weekly intervals, until product'use-by' date was reached. Enumeration methods utilised M17 agar for streptococci, MRS pH 5.3 agar for Lactobacillus delbrueckii subsp. bulgaricus, MRS + 0.2% ox bile for L. acidophilus, and Bifidus-blood agar for bifidobacteria. For product held at 4°C, Streptococcus thermophilus survival was universally highest in all four products, with lowest counts being 4.1 x 10 8 cfu/g after six weeks. A single yogurt contained L. delbrueckii subsp. bulgaricus, which also survived well. Minimum counts were 7.4 x 10 6 cfu/g at ...
ABSTRACT My view of bioprocessing is influenced by a career-long interest in gut fermentation. My... more ABSTRACT My view of bioprocessing is influenced by a career-long interest in gut fermentation. My Masters research and my PhD were on the biochemistry and microbiology of silage fermentation. Silage of course is the fermentation of plant materials usually by naturally-occurring bacteria, although inoculants of lactic acid bacteria, such as Lactobacillus plantarum are increasingly being used to make silage these days. Depending on the environmental conditions imposed on the plant material (e.g. anaerobic conditions, moisture content, sugar content), the mixed culture fermentation could be shifted to produce predominantly lactic acid, rather than acetic and butyric acids which tended to dominate if the silage was badly made. Silage is but one example of a number of products made by natural mixed culture processes, where the quality of the product is determined by the conditions imposed on the process, and the nature of the original substrate. Other examples include wine, cider and beer fermentations, cheese manufacture, and a variety of fermented milks. There are a large number of traditional food and beverage fermentations continuing to be used particularly in tropical countries, where acidification by lactic acid production is an important form of preservation of the food or beverage, in the absence of refrigeration. These processes, many very ancient, are all forms of bioprocessing. They appear relatively uncontrolled and irreproducible, but this is not the case, as they have been optimised over time, and the critical control points acknowledged by trial and error...
Culture viability over a 12-month period was compared between commercial frozen concentrates of L... more Culture viability over a 12-month period was compared between commercial frozen concentrates of Lactobacillus acidophilus, Bifidobacterium lactis and Lactobacillus paracasei subsp. paracasei when incorporated into a low-fat ice-cream and stored at -25°C. Comparisons included survival in a standard full-fat product versus the low-fat formulation, the effects of adding the prebiotic-resistant starch Hi Maize, and viability of bacteria at three different culture dosage levels. The initial freezing and churning stage of converting mix into ice-cream had the greatest effect on culture viability in most cases. Survival rates of L. acidophilus were significantly (p Cette etude evalue l'addition directe de concentrats congeles de cultures de Lactobacillus acidophilus, Bifibobacterium lactis et L. paracasei subsp. paracasei a un melange de creme glacee et la survie des cultures pendant 12 mois. Les effets sur la viabilite des cultures dans des formulations allegees et standards sont auss...
... has received approval to produce and market a galactooligosaccharide product in ... 1994)4. T... more ... has received approval to produce and market a galactooligosaccharide product in ... 1994)4. They are manufactured bytwodifferentprocesses,r Galactooligosaccharides aDGlul4DGall61,wheren ...Novel production techniques that use improved enzymes, purificationsys tems and or ...
Thirty-two bacterial isolates from species commonly used in yoghurts and fermented milks were exa... more Thirty-two bacterial isolates from species commonly used in yoghurts and fermented milks were examined for their ability to synthesise or utilise folate during fermentation of skim milk. The organisms examined included the traditional yoghurt starter cultures, Lactobacillus delbrueckii ...
Abstract Shoot material of Leucaena leucocephala (leucaena), Calliandra calothyrsus and Calliandr... more Abstract Shoot material of Leucaena leucocephala (leucaena), Calliandra calothyrsus and Calliandra surinamensis was incubated for 12, 24, 36 and 48 h in nylon bags suspended in the rumen of a steer and losses of various components of the feed measured. Leucaena had much faster rates of loss of dry matter (DM), N, P and Ca. Leucaena had also a faster S loss than Calliandra calothyrsus , whereas C. surinamensis showed very high levels of soluble S. Loss of neutral detergent fibre (NDF) after 48 h was also far greater with leucaena than C. surinamensis (46.4% vs. 10.3%), whereas with C. calothyrsus there appeared to be an increase in NDF and ADF. For all species, acid detergent lignin (ADL) appeared to be higher than initial plant values throughout the period of incubation; markedly so for C. calothyrsus . The Calliandra spp. had high levels of silica and Al in their DM. Our findings and other published results, indicate that the Calliandra spp. investigated may not be a suitable alternative to leucaena as a ruminant feed.
Sheep and cattle in metabolism cages were used to measure the voluntary intake and dry matter dig... more Sheep and cattle in metabolism cages were used to measure the voluntary intake and dry matter digestibility of three cuts of buffel grass (Cenchrus ciliaris) . The cattle digested the feeds better and ate more on a metabolic mass basis (WO*75). The three feeds were ranked similarly by sheep and cattle, but the extent of the differences in digestibility values between sheep and cattle varied. Using sheep, it was not possible to predict the absolute intake of digestible dry matter of a feed by cattle. In vitro digestibility determined at another laboratory agreed well with the in vivo sheep values obtained but did not agree with in vivo cattle digestibilities. It was suggested that measurement of small differences in nutritional value of pasture species using sheep may not be meaningful if the pastures , are to be used by cattle. Two of the feeds provided a below-maintenance feed for the sheep, but an above-maintenance feed for cattle.
... Dr Annabelle Bennett BSc, PhD, LLB Barrister at Law. Dr Angela Delves BAppBiol, PhD Academic ... more ... Dr Annabelle Bennett BSc, PhD, LLB Barrister at Law. Dr Angela Delves BAppBiol, PhD Academic Registrar, Australian National University. ... Professor Jim Pittard BSc, MSc, PhD, DSc, FAA Head, Department of Microbiology, University of Melbourne. ...
Eight bacteremia-associated Lactobacillus strains were evaluated in vitro for the ability to adhe... more Eight bacteremia-associated Lactobacillus strains were evaluated in vitro for the ability to adhere to human intestinal mucosa and to aggregate platelets. Adherence varied significantly among the strains, and platelet aggregation was induced by three strains. In conclusion, strong binding ability does not appear to be a prerequisite for the involvement of lactobacilli in bacteremia or to their ability to aggregate platelets.
... Alternatives to antibiotics are urgently sought, and there has been considerable interest in ... more ... Alternatives to antibiotics are urgently sought, and there has been considerable interest in the use of both prebiotics and probiotics in animal feeds to aid production. Although they have shown some promise (182183), further research is needed into their application within an ...
Many tropical pastures are very low in sodium (Playne 1970) yet few experiments have shown respon... more Many tropical pastures are very low in sodium (Playne 1970) yet few experiments have shown responses which could be attributed to supplemen-tation of cattle with this element. Recently Murphy and Plasto (1973) have reported an unequivocal growth response to sodium chloride supplemen-tation of grazing beef cows and their calves. This study reports the growth responses and saliva sodium levels for a group of four 2 year old Droughtmaster 'steers (group 1) grazing blue grass (Bothriochloa decipiens var. Cloncurriensis) dominant pastures known to be low in sodium (0.012%). These are compared with results for a further nine Droughtmaster steers (groups 2 and 3) grazing spear grass (Heteropogon contortus).in combination with Townsville stylo (Stylosanthes humilis) which contained 0.046 % and 0.112 % sodium respectively. Five ani-mals from the spear grass pasture (group 2) were then introduced to the blue grass pasture on 13.xii.74 and measurements of live weight and saliva sodium.mad...
Two ways are explored of using as fuels, the considerable amounts of lignocellulosic materials av... more Two ways are explored of using as fuels, the considerable amounts of lignocellulosic materials available in Australia. Fermentation of lignocellulose by mixed cultures of bacteria to yield volatile fatty acids is discussed, together with separation of the acids from the aqueous fermentation liquor and their conversion to ketones. Ketones and their derivatives are compared with alcohols and ethers in terms of their value as fuels or fuel additives. Cost analysis indicates that the process could be competitive with other proposed processes for obtaining alternative liquid fuels. Gasification and pyrolysis of biomass is reviewed. An opportunity now exists for producing low energy gas from biomass for use in close coupled boilers, furnaces and kilns in place of lpg or liquid petroleum fuels. Despite much progress towards commercial plants, it will be some time before new technology based on catalysed gasifiers and very fast pyrolysis will be economically competitive in Australia (a). Th...
Biotechnology and genetic engineering are defined and their applications in the dairy industry de... more Biotechnology and genetic engineering are defined and their applications in the dairy industry described for pasture and animal improvement, and for dairy product processing in the factory. Problems in establishing new biotechnologies in the dairy industry and the regulatory hurdles that have to be overcome are discussed. Gene probes and monoclonal antibodies as diagnostics, bovine somatotropin to increase milk production, recombinant DNA-rennin in cheesemaking, recombinant-DNA starter cultures, and enzymes to convert lactose to oligosaccharides are used as examples relevant to the dairy industry. It is advocated that the dairy industry develop a biotechnology policy and an education programme, and actively consider joint ventures with dedicated biotechnology companies.
The investigation of various media formulations, using pure cultures and commercial yogurts, prov... more The investigation of various media formulations, using pure cultures and commercial yogurts, provided the basis for selecting suitable methods to enumerate probiotic cultures. Full and reduced-fat yogurts from four manufacturers of commercial probiotic yogurts were sampled one day post manufacture and analysed for constitutive microflora. Samples were stored at 4°C and 10°c, with subsequent sampling and testing at approximately two weekly intervals, until product'use-by' date was reached. Enumeration methods utilised M17 agar for streptococci, MRS pH 5.3 agar for Lactobacillus delbrueckii subsp. bulgaricus, MRS + 0.2% ox bile for L. acidophilus, and Bifidus-blood agar for bifidobacteria. For product held at 4°C, Streptococcus thermophilus survival was universally highest in all four products, with lowest counts being 4.1 x 10 8 cfu/g after six weeks. A single yogurt contained L. delbrueckii subsp. bulgaricus, which also survived well. Minimum counts were 7.4 x 10 6 cfu/g at ...
ABSTRACT My view of bioprocessing is influenced by a career-long interest in gut fermentation. My... more ABSTRACT My view of bioprocessing is influenced by a career-long interest in gut fermentation. My Masters research and my PhD were on the biochemistry and microbiology of silage fermentation. Silage of course is the fermentation of plant materials usually by naturally-occurring bacteria, although inoculants of lactic acid bacteria, such as Lactobacillus plantarum are increasingly being used to make silage these days. Depending on the environmental conditions imposed on the plant material (e.g. anaerobic conditions, moisture content, sugar content), the mixed culture fermentation could be shifted to produce predominantly lactic acid, rather than acetic and butyric acids which tended to dominate if the silage was badly made. Silage is but one example of a number of products made by natural mixed culture processes, where the quality of the product is determined by the conditions imposed on the process, and the nature of the original substrate. Other examples include wine, cider and beer fermentations, cheese manufacture, and a variety of fermented milks. There are a large number of traditional food and beverage fermentations continuing to be used particularly in tropical countries, where acidification by lactic acid production is an important form of preservation of the food or beverage, in the absence of refrigeration. These processes, many very ancient, are all forms of bioprocessing. They appear relatively uncontrolled and irreproducible, but this is not the case, as they have been optimised over time, and the critical control points acknowledged by trial and error...
Culture viability over a 12-month period was compared between commercial frozen concentrates of L... more Culture viability over a 12-month period was compared between commercial frozen concentrates of Lactobacillus acidophilus, Bifidobacterium lactis and Lactobacillus paracasei subsp. paracasei when incorporated into a low-fat ice-cream and stored at -25°C. Comparisons included survival in a standard full-fat product versus the low-fat formulation, the effects of adding the prebiotic-resistant starch Hi Maize, and viability of bacteria at three different culture dosage levels. The initial freezing and churning stage of converting mix into ice-cream had the greatest effect on culture viability in most cases. Survival rates of L. acidophilus were significantly (p Cette etude evalue l'addition directe de concentrats congeles de cultures de Lactobacillus acidophilus, Bifibobacterium lactis et L. paracasei subsp. paracasei a un melange de creme glacee et la survie des cultures pendant 12 mois. Les effets sur la viabilite des cultures dans des formulations allegees et standards sont auss...
... has received approval to produce and market a galactooligosaccharide product in ... 1994)4. T... more ... has received approval to produce and market a galactooligosaccharide product in ... 1994)4. They are manufactured bytwodifferentprocesses,r Galactooligosaccharides aDGlul4DGall61,wheren ...Novel production techniques that use improved enzymes, purificationsys tems and or ...
Thirty-two bacterial isolates from species commonly used in yoghurts and fermented milks were exa... more Thirty-two bacterial isolates from species commonly used in yoghurts and fermented milks were examined for their ability to synthesise or utilise folate during fermentation of skim milk. The organisms examined included the traditional yoghurt starter cultures, Lactobacillus delbrueckii ...
Abstract Shoot material of Leucaena leucocephala (leucaena), Calliandra calothyrsus and Calliandr... more Abstract Shoot material of Leucaena leucocephala (leucaena), Calliandra calothyrsus and Calliandra surinamensis was incubated for 12, 24, 36 and 48 h in nylon bags suspended in the rumen of a steer and losses of various components of the feed measured. Leucaena had much faster rates of loss of dry matter (DM), N, P and Ca. Leucaena had also a faster S loss than Calliandra calothyrsus , whereas C. surinamensis showed very high levels of soluble S. Loss of neutral detergent fibre (NDF) after 48 h was also far greater with leucaena than C. surinamensis (46.4% vs. 10.3%), whereas with C. calothyrsus there appeared to be an increase in NDF and ADF. For all species, acid detergent lignin (ADL) appeared to be higher than initial plant values throughout the period of incubation; markedly so for C. calothyrsus . The Calliandra spp. had high levels of silica and Al in their DM. Our findings and other published results, indicate that the Calliandra spp. investigated may not be a suitable alternative to leucaena as a ruminant feed.
Sheep and cattle in metabolism cages were used to measure the voluntary intake and dry matter dig... more Sheep and cattle in metabolism cages were used to measure the voluntary intake and dry matter digestibility of three cuts of buffel grass (Cenchrus ciliaris) . The cattle digested the feeds better and ate more on a metabolic mass basis (WO*75). The three feeds were ranked similarly by sheep and cattle, but the extent of the differences in digestibility values between sheep and cattle varied. Using sheep, it was not possible to predict the absolute intake of digestible dry matter of a feed by cattle. In vitro digestibility determined at another laboratory agreed well with the in vivo sheep values obtained but did not agree with in vivo cattle digestibilities. It was suggested that measurement of small differences in nutritional value of pasture species using sheep may not be meaningful if the pastures , are to be used by cattle. Two of the feeds provided a below-maintenance feed for the sheep, but an above-maintenance feed for cattle.
... Dr Annabelle Bennett BSc, PhD, LLB Barrister at Law. Dr Angela Delves BAppBiol, PhD Academic ... more ... Dr Annabelle Bennett BSc, PhD, LLB Barrister at Law. Dr Angela Delves BAppBiol, PhD Academic Registrar, Australian National University. ... Professor Jim Pittard BSc, MSc, PhD, DSc, FAA Head, Department of Microbiology, University of Melbourne. ...
Eight bacteremia-associated Lactobacillus strains were evaluated in vitro for the ability to adhe... more Eight bacteremia-associated Lactobacillus strains were evaluated in vitro for the ability to adhere to human intestinal mucosa and to aggregate platelets. Adherence varied significantly among the strains, and platelet aggregation was induced by three strains. In conclusion, strong binding ability does not appear to be a prerequisite for the involvement of lactobacilli in bacteremia or to their ability to aggregate platelets.
... Alternatives to antibiotics are urgently sought, and there has been considerable interest in ... more ... Alternatives to antibiotics are urgently sought, and there has been considerable interest in the use of both prebiotics and probiotics in animal feeds to aid production. Although they have shown some promise (182183), further research is needed into their application within an ...
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