The research was first to perform the utilization of novel and cheap pectin crude extract from Krung Kha Mao leaves （Cissampelos pareira L.） to immobilize cells of Lactobacillus casei subsp, rhamnosus TISTR 108 and ...The research was first to perform the utilization of novel and cheap pectin crude extract from Krung Kha Mao leaves （Cissampelos pareira L.） to immobilize cells of Lactobacillus casei subsp, rhamnosus TISTR 108 and Lactobacillus delbrueckii subsp, bulgaricus TISTR 1339 for lactic acid production, the optimum condition of immobilized cells was produced significantly at 5% of probability, that the highest lactic acid has been 38.50 and 33.66 g/L in steady state of whey medium for 96 and 108 h, respectively. Both strains were immobilized by 4% （w/w） of pectin crude extract from Krung Kha Mao （KKM pectin） leaves, 1.52 mm inner diameters of silicone tube and 5% （v/v） inoculum for immobilization. Efficiency of lactic acid production was compared by immobilized cells ofL. casei subsp, rhamnosus TISTR 108 when KKM pectin, commercial citrus pectin, commercial apple pectin and sodium alginate were used as supporting materials to produce lactic acid 38.50, 38.76, 30.43 and 34.56 g/L, respectively, the productivity of lactic acid has been 0.40, 0.40, 0.36 and 0.36 g/L h, respectively.展开更多
Bioremediation of organophosphorus pesticides in contaminated foodstuffs using probiotics has been increasingly under the spotlight in recent years,though the biodegradation mechanism and derived intermediate products...Bioremediation of organophosphorus pesticides in contaminated foodstuffs using probiotics has been increasingly under the spotlight in recent years,though the biodegradation mechanism and derived intermediate products remain unclear.This study aimed to help fill this knowledge gap and examined the degradation mechanism of organophosphorus pesticide,chlorpyrifos,in milk by Lactobacillus delbrueckii ssp.bulgaricus using gas chromatography-tandem mass spectrometry(GC-MS/MS)combined with transcriptome analysis.After the strain was cultured for 20 h in the presence of chlorpyrifos,differential expressions of 383 genes were detected,including genes probably implicated during chlorpyrifos degradation such as those related to hydrolase,phosphoesterase,diphosphatase,oxidoreductase,dehydratase,as well as membrane transporters.GC-MS/MS analysis revealed the changes of secondary metabolites in L.bulgaricus during milk fermentation due to chlorpyrifos stress.6-Methylhexahydro-2H-azepin-2-one,2,6-dihydroxypyridine and methyl 2-aminooxy-4-methylpentanoate as intermediates,along with the proposed pathways,might be involved in chlorpyrifos biodegradation by L.bulgaricus.展开更多
Lactobacillus delbrueckii subsp. bulgaricus, which has been widely used as a fermented milk starter, is a type of probiotic, and certain strains are able to produce exopolysaccharide (EPS). EPS produced from L. bulgar...Lactobacillus delbrueckii subsp. bulgaricus, which has been widely used as a fermented milk starter, is a type of probiotic, and certain strains are able to produce exopolysaccharide (EPS). EPS produced from L. bulgaricus contributes to the physical and biological function of dairy products by regulating immune response, and this tendency seems to place EPS with acidic groups. To date, six types of chemical structure have been determined and are basically composed from glucose (Glc), galactose (Gal), and rhamnose (Rha). Eps clusters on chromosome DNA control the EPS synthesis and are transcribed as one mRNA 14 genes with 18kb on L. bulgaricus Lfi5. Furthermore, L. bulgaricus is able to utilize lactose (Lac) as carbohydrate source, repeating units of EPS are synthesized from Glc 6-phosphate, generated by an Embden-Meyerhof (EM) pathway in cellular carbohydrate assimilation. This review discusses EPS produced from L. bulgaricus.展开更多
The sterilization conditions between experiment and dairy industrial level are different and concern about influence on product’s qualities. In this study, the fermentation properties of Streptococcus thermophilus, a...The sterilization conditions between experiment and dairy industrial level are different and concern about influence on product’s qualities. In this study, the fermentation properties of Streptococcus thermophilus, alone and in combination with Lactobacillus delbrueckii subsp. bulgaricus, were evaluated in skim milk that had been subjected to distinct sterilization conditions. Growth, organic acid generation, and EPS production were determined using pasteurized or autoclaved milk. When S. thermophilus was cultivated in pasteurized skim milk, the growth was strain-dependent. On the other hand, growth of S. thermophilus was accelerated in autoclaved milk. Exocellular polysaccharide (EPS) production by L. bulgaricus was not affected by the combination of S. thermophilus strains. Thus, we observed that yogurt fermented by L. bulgaricus was minimally affected by the combination of S. thermophilus strains;growth of L. bulgaricus was maintained under the constant environment. These results should facilitate the development of fermented milk produced from L. bulgaricus in the dairy industry.展开更多
文摘The research was first to perform the utilization of novel and cheap pectin crude extract from Krung Kha Mao leaves （Cissampelos pareira L.） to immobilize cells of Lactobacillus casei subsp, rhamnosus TISTR 108 and Lactobacillus delbrueckii subsp, bulgaricus TISTR 1339 for lactic acid production, the optimum condition of immobilized cells was produced significantly at 5% of probability, that the highest lactic acid has been 38.50 and 33.66 g/L in steady state of whey medium for 96 and 108 h, respectively. Both strains were immobilized by 4% （w/w） of pectin crude extract from Krung Kha Mao （KKM pectin） leaves, 1.52 mm inner diameters of silicone tube and 5% （v/v） inoculum for immobilization. Efficiency of lactic acid production was compared by immobilized cells ofL. casei subsp, rhamnosus TISTR 108 when KKM pectin, commercial citrus pectin, commercial apple pectin and sodium alginate were used as supporting materials to produce lactic acid 38.50, 38.76, 30.43 and 34.56 g/L, respectively, the productivity of lactic acid has been 0.40, 0.40, 0.36 and 0.36 g/L h, respectively.
基金supported by Natural Science Foundation of China(41907357)Natural Science Foundation of Shandong(ZR2019PC048)the Key R&D project of Shandong Province(2021TZXD007).
文摘Bioremediation of organophosphorus pesticides in contaminated foodstuffs using probiotics has been increasingly under the spotlight in recent years,though the biodegradation mechanism and derived intermediate products remain unclear.This study aimed to help fill this knowledge gap and examined the degradation mechanism of organophosphorus pesticide,chlorpyrifos,in milk by Lactobacillus delbrueckii ssp.bulgaricus using gas chromatography-tandem mass spectrometry(GC-MS/MS)combined with transcriptome analysis.After the strain was cultured for 20 h in the presence of chlorpyrifos,differential expressions of 383 genes were detected,including genes probably implicated during chlorpyrifos degradation such as those related to hydrolase,phosphoesterase,diphosphatase,oxidoreductase,dehydratase,as well as membrane transporters.GC-MS/MS analysis revealed the changes of secondary metabolites in L.bulgaricus during milk fermentation due to chlorpyrifos stress.6-Methylhexahydro-2H-azepin-2-one,2,6-dihydroxypyridine and methyl 2-aminooxy-4-methylpentanoate as intermediates,along with the proposed pathways,might be involved in chlorpyrifos biodegradation by L.bulgaricus.
文摘Lactobacillus delbrueckii subsp. bulgaricus, which has been widely used as a fermented milk starter, is a type of probiotic, and certain strains are able to produce exopolysaccharide (EPS). EPS produced from L. bulgaricus contributes to the physical and biological function of dairy products by regulating immune response, and this tendency seems to place EPS with acidic groups. To date, six types of chemical structure have been determined and are basically composed from glucose (Glc), galactose (Gal), and rhamnose (Rha). Eps clusters on chromosome DNA control the EPS synthesis and are transcribed as one mRNA 14 genes with 18kb on L. bulgaricus Lfi5. Furthermore, L. bulgaricus is able to utilize lactose (Lac) as carbohydrate source, repeating units of EPS are synthesized from Glc 6-phosphate, generated by an Embden-Meyerhof (EM) pathway in cellular carbohydrate assimilation. This review discusses EPS produced from L. bulgaricus.
文摘The sterilization conditions between experiment and dairy industrial level are different and concern about influence on product’s qualities. In this study, the fermentation properties of Streptococcus thermophilus, alone and in combination with Lactobacillus delbrueckii subsp. bulgaricus, were evaluated in skim milk that had been subjected to distinct sterilization conditions. Growth, organic acid generation, and EPS production were determined using pasteurized or autoclaved milk. When S. thermophilus was cultivated in pasteurized skim milk, the growth was strain-dependent. On the other hand, growth of S. thermophilus was accelerated in autoclaved milk. Exocellular polysaccharide (EPS) production by L. bulgaricus was not affected by the combination of S. thermophilus strains. Thus, we observed that yogurt fermented by L. bulgaricus was minimally affected by the combination of S. thermophilus strains;growth of L. bulgaricus was maintained under the constant environment. These results should facilitate the development of fermented milk produced from L. bulgaricus in the dairy industry.
