Production and quality of vinegar from mango juice was evaluated using a two steps production procedure. The first step of fermentation was done using Saccharomyces cerevisae KVL013 for 7 days. The second step, an ace...Production and quality of vinegar from mango juice was evaluated using a two steps production procedure. The first step of fermentation was done using Saccharomyces cerevisae KVL013 for 7 days. The second step, an acetic fermentation was realized using two acetic acid bacteria: A. tropicalis CRSBAN-BVA1 and A. tropicalis CRSBAN-BVK2 for 21 days. Several parameters of the vinegar produced such as physico-chemical and sensory properties were determined. Microbial density during each step was monitored. Results showed that pH, alcoholic and acetic acid contents of vinegar were respectively 2.97%, 7% and 4.54% g/ml respectively by using A. tropicalis CRSBAN-BVA1 and 3.02%, 7% and 4.32% g/ml with A. tropicalis CRSBAN-BVK2. Sensory evaluation revealed that the vinegar was acceptable to the panellists. Results of microbial density showed that the maximum concentration of cell biomass produced was 4.32 × 10<sup>8</sup> and 4.25 × 10<sup>8</sup> CFU/ml respectively for CRSBAN-BVA1 and CRSBAN-BVK2.展开更多
The gram-negative bacterium Acetobacter xylinum synthesizes an extracellular ribbon of cellulose microfibrils that possess unique structural and mechanical properties when compared to higher plant cellulose. All four...The gram-negative bacterium Acetobacter xylinum synthesizes an extracellular ribbon of cellulose microfibrils that possess unique structural and mechanical properties when compared to higher plant cellulose. All four genes in the cellulose-synthesizing operon (ayacs operon) of A. xylinum Ay201 were amplified by polymerase chain reaction (PCR) using oligonucleotide primers designed according to published acs operon sequence of A. xylinum ATCC 53582. Alignment of the two operons showed that they were highly homologous (98% similarity, 97% identity). AcsA and acsB gene were cloned in pCAMBIA 1301 vector while acsC and acsD were cloned in pCOB302-3 under the control of CaM 35S promoter. The constructs were introduced into cotton by the pollen-tube-pathway method and seeds obtained from putative transgenic plants were germinated on media containing hygromycin and phosphinothricin (PPT). Five seedlings out of 934 seeds were proved to contain all four foreign genes by PCR amplification. This is the first time that a whole operon encoding four different bacterial enzymes with various biological functions is transformed into cultivated cotton plants.展开更多
Thermotolerant microorganisms were collected, identified and characterized under different physiological conditions from various rotten fruits in Bangladesh for vinegar production. Among the 15-isolates characterized ...Thermotolerant microorganisms were collected, identified and characterized under different physiological conditions from various rotten fruits in Bangladesh for vinegar production. Among the 15-isolates characterized previously, the strains F-1, F-3 and F-10 represented Staphylococcus, Bacillus and Acetobacter spp., respectively. After checking various parameters for growth, acetic acid production rate was optimized further. Among the 3-starins analyzed here, the strain F-10 gave maximum acetic acid (7.0 g/100 ml) at 37°C in 2% ethanol concentration. The strain F-10 is capable of producing high yield of acetic acid at relatively high temperature, which is an ideal condition for vinegar production, which may reduce the water cooling expenses as well as the risk of contamination.展开更多
BACKGROUND At present,there is no ideal method to cure diabetes,and there are few reports on the treatment of diabetes with probiotics.AIM To propose a method for preparing a new type of chromium-and zinc-rich Acetoba...BACKGROUND At present,there is no ideal method to cure diabetes,and there are few reports on the treatment of diabetes with probiotics.AIM To propose a method for preparing a new type of chromium-and zinc-rich Acetobacter aceti(A.aceti)and explore its ability to enhance the hypoglycemic effects of probiotics in the treatment of diabetes.METHODS A.aceti was cultured in a liquid medium that contained chromium trichloride and zinc chloride,both at a concentration of 64 mg/mL,with the initial concentration of the bacterial solution 1×10^(4) CFU/mL.After the bacterial solution had been inducted for 48 h,the culture media was changed and the induction was repeated once.The levels of chromium and zinc in the bacteria were detected by inductively coupled plasma mass spectrometry,and the contents of NADH and glucose dehydrogenase were determined using an NAD/NADH kit and glucose dehydrogenase kit,respectively.Streptozotocin was used to establish a mouse model to evaluate the hypoglycemic effects of the proposed chromium-and zincrich A.aceti.Ten-times the therapeutic dose was administered to evaluate its biological safety.The effect on MIN6 islet cells was also assessed in vitro.RESULTS The levels of chromium metal,metallic zinc,NADH coenzyme,and glucose dehydrogenase in A.aceti prepared by this method were 28.58-34.34 mg/kg,5.35-7.52 mg/kg,5.13-7.26μM,and 446.812-567.138 U/g,respectively.The use of these bacteria resulted in a better hypoglycemic effect than metformin,promoting the repair of tissues and cells of pancreatic islets in vivo and facilitating the growth of MIN6 pancreatic islet cells and increasing insulin secretion in vitro.Ten-times the therapeutic dose of treatment was non-toxic to mice.CONCLUSION Chromium trichloride and zinc chloride can be employed to induce the preparation of chromiumand zinc-rich A.aceti,which can then promote the hypoglycemic effect found in normal A.aceti.The bacteria biotransforms the chromium and zinc in a way that could increase their safety as a treatment for diabetes.展开更多
The Acetobacter estunensis Rep34 protein participates in the replication of bacterial plasmid pGP2. The Rep34 protein of the A. estunensis, was cloned to the expression vector, that ensure fusion with a His-tag sequen...The Acetobacter estunensis Rep34 protein participates in the replication of bacterial plasmid pGP2. The Rep34 protein of the A. estunensis, was cloned to the expression vector, that ensure fusion with a His-tag sequence (Rep34 His-tagged), over-expressed in Escherichia coli and purified by metal-affinity chromatography to yield a highly purified and active protein. On this purified protein number different activities and motifs were detected. DNA band-shift assays showed that the Rep34 His-tagged protein bound to the regulation region for replication on the linear double-stranded DNA. In the protein was determined phosphatase activity, ATPase activity and protein is possible to unwind double strand DNA.展开更多
In this paper, the authors analyzed the correlation between the microbiological stability of white wines and the content of sulfur dioxide, which influences the main redox processes that take place in the technologica...In this paper, the authors analyzed the correlation between the microbiological stability of white wines and the content of sulfur dioxide, which influences the main redox processes that take place in the technological stages of the wine. The consecutive, parallel and spontaneous development of several redox processes and their impact on the quality, microbiological and crystalline stability of white wines were examined. The reduction of additive and subtractive technological interventions, of the amounts of adjuvants (sulphurous anhydride) is essential for the production of organic wines.展开更多
玉米淀粉黄浆水是生产淀粉过程中排放的高浓度有机废水,以其作为Acetobacter xylinum DS398的基础培养基发酵细菌纤维素。采用Plackett-Burman设计和Box-Behnken响应面分析法对培养基成分进行优化,并对产物进行表征。以纤维素干重为响应...玉米淀粉黄浆水是生产淀粉过程中排放的高浓度有机废水,以其作为Acetobacter xylinum DS398的基础培养基发酵细菌纤维素。采用Plackett-Burman设计和Box-Behnken响应面分析法对培养基成分进行优化,并对产物进行表征。以纤维素干重为响应值,从7个相关影响因素筛选出3个显著因子:蔗糖、磷酸二氢钾和乙醇。在此基础上,根据Box-Behnken响应面分析法确定以上三因素的最佳浓度。最优的玉米淀粉黄浆水培养基组分为:玉米黄浆水稀释比1∶4,蔗糖3.32 g/100 m L,CaCl_20.3 g/100 m L,KH_2PO_40.12 g/100 m L,Mg SO_40.05 g/100 m L,柠檬酸0.2 g/100 m L,乙醇1.50 m L/100 m L,细菌纤维素产量达到1.11 g/100 m L,为优化前的1.63倍。结果表明经优化后黄浆水培养基能够满足Acetobacter xylinum生长代谢的需要,细菌纤维素产量得到显著提高;同时傅立叶红外光谱图和场发射扫描电镜图显示产物是纯度较高的纤维素,微观结构与椰果相似。展开更多
Vinegars are commonly used as food condiments and preservatives. Apple cider vinegar (ACV) is also used in the Ayurvedic pharmaceutical industry because of its medicinal properties. Since specifically selected starter...Vinegars are commonly used as food condiments and preservatives. Apple cider vinegar (ACV) is also used in the Ayurvedic pharmaceutical industry because of its medicinal properties. Since specifically selected starter cultures for commercial vinegar production are not readily available, apple juice supplemented with sugar is commonly inoculated with a microbiologically undefined culture obtained from the previous batch of ACV. The present work focuses on the isolation of yeasts and acetic acid bacteria from ACV and the preparation of a starter culture. ACV was produced in a bench scale bioreactor using a traditional fermentation process wherein an acetic acid concentration of 3.8% was obtained after three weeks. Several acetic acid bacteria (AAB) were isolated from ACV using selective media. Microscopy revealed the cultures to be gram negative to gram variable short rods. The growth pattern of the isolates on differential media and biochemical tests suggested the presence of Acetobacter and Gluconobacter species. Ten potent isolates were selected for starter culture preparation. Two consortia were formulated with five AAB isolates in each along with a yeast isolate and used for ACV production, wherein an acetic acid concentration of 4.2% - 4.9% was obtained in 10 - 12 days. Thus, these two starter cultures with locally isolated AAB can be used for the commercial production of apple cider vinegar.展开更多
文摘Production and quality of vinegar from mango juice was evaluated using a two steps production procedure. The first step of fermentation was done using Saccharomyces cerevisae KVL013 for 7 days. The second step, an acetic fermentation was realized using two acetic acid bacteria: A. tropicalis CRSBAN-BVA1 and A. tropicalis CRSBAN-BVK2 for 21 days. Several parameters of the vinegar produced such as physico-chemical and sensory properties were determined. Microbial density during each step was monitored. Results showed that pH, alcoholic and acetic acid contents of vinegar were respectively 2.97%, 7% and 4.54% g/ml respectively by using A. tropicalis CRSBAN-BVA1 and 3.02%, 7% and 4.32% g/ml with A. tropicalis CRSBAN-BVK2. Sensory evaluation revealed that the vinegar was acceptable to the panellists. Results of microbial density showed that the maximum concentration of cell biomass produced was 4.32 × 10<sup>8</sup> and 4.25 × 10<sup>8</sup> CFU/ml respectively for CRSBAN-BVA1 and CRSBAN-BVK2.
文摘The gram-negative bacterium Acetobacter xylinum synthesizes an extracellular ribbon of cellulose microfibrils that possess unique structural and mechanical properties when compared to higher plant cellulose. All four genes in the cellulose-synthesizing operon (ayacs operon) of A. xylinum Ay201 were amplified by polymerase chain reaction (PCR) using oligonucleotide primers designed according to published acs operon sequence of A. xylinum ATCC 53582. Alignment of the two operons showed that they were highly homologous (98% similarity, 97% identity). AcsA and acsB gene were cloned in pCAMBIA 1301 vector while acsC and acsD were cloned in pCOB302-3 under the control of CaM 35S promoter. The constructs were introduced into cotton by the pollen-tube-pathway method and seeds obtained from putative transgenic plants were germinated on media containing hygromycin and phosphinothricin (PPT). Five seedlings out of 934 seeds were proved to contain all four foreign genes by PCR amplification. This is the first time that a whole operon encoding four different bacterial enzymes with various biological functions is transformed into cultivated cotton plants.
文摘Thermotolerant microorganisms were collected, identified and characterized under different physiological conditions from various rotten fruits in Bangladesh for vinegar production. Among the 15-isolates characterized previously, the strains F-1, F-3 and F-10 represented Staphylococcus, Bacillus and Acetobacter spp., respectively. After checking various parameters for growth, acetic acid production rate was optimized further. Among the 3-starins analyzed here, the strain F-10 gave maximum acetic acid (7.0 g/100 ml) at 37°C in 2% ethanol concentration. The strain F-10 is capable of producing high yield of acetic acid at relatively high temperature, which is an ideal condition for vinegar production, which may reduce the water cooling expenses as well as the risk of contamination.
基金the Fourth Self-funded Projects of Baise Scientific Research and Technology Development Plan,No.20203402School-level Scientific Research Project of Youjiang Medical University for Nationalities,No.yy2021sk029.
文摘BACKGROUND At present,there is no ideal method to cure diabetes,and there are few reports on the treatment of diabetes with probiotics.AIM To propose a method for preparing a new type of chromium-and zinc-rich Acetobacter aceti(A.aceti)and explore its ability to enhance the hypoglycemic effects of probiotics in the treatment of diabetes.METHODS A.aceti was cultured in a liquid medium that contained chromium trichloride and zinc chloride,both at a concentration of 64 mg/mL,with the initial concentration of the bacterial solution 1×10^(4) CFU/mL.After the bacterial solution had been inducted for 48 h,the culture media was changed and the induction was repeated once.The levels of chromium and zinc in the bacteria were detected by inductively coupled plasma mass spectrometry,and the contents of NADH and glucose dehydrogenase were determined using an NAD/NADH kit and glucose dehydrogenase kit,respectively.Streptozotocin was used to establish a mouse model to evaluate the hypoglycemic effects of the proposed chromium-and zincrich A.aceti.Ten-times the therapeutic dose was administered to evaluate its biological safety.The effect on MIN6 islet cells was also assessed in vitro.RESULTS The levels of chromium metal,metallic zinc,NADH coenzyme,and glucose dehydrogenase in A.aceti prepared by this method were 28.58-34.34 mg/kg,5.35-7.52 mg/kg,5.13-7.26μM,and 446.812-567.138 U/g,respectively.The use of these bacteria resulted in a better hypoglycemic effect than metformin,promoting the repair of tissues and cells of pancreatic islets in vivo and facilitating the growth of MIN6 pancreatic islet cells and increasing insulin secretion in vitro.Ten-times the therapeutic dose of treatment was non-toxic to mice.CONCLUSION Chromium trichloride and zinc chloride can be employed to induce the preparation of chromiumand zinc-rich A.aceti,which can then promote the hypoglycemic effect found in normal A.aceti.The bacteria biotransforms the chromium and zinc in a way that could increase their safety as a treatment for diabetes.
文摘The Acetobacter estunensis Rep34 protein participates in the replication of bacterial plasmid pGP2. The Rep34 protein of the A. estunensis, was cloned to the expression vector, that ensure fusion with a His-tag sequence (Rep34 His-tagged), over-expressed in Escherichia coli and purified by metal-affinity chromatography to yield a highly purified and active protein. On this purified protein number different activities and motifs were detected. DNA band-shift assays showed that the Rep34 His-tagged protein bound to the regulation region for replication on the linear double-stranded DNA. In the protein was determined phosphatase activity, ATPase activity and protein is possible to unwind double strand DNA.
文摘In this paper, the authors analyzed the correlation between the microbiological stability of white wines and the content of sulfur dioxide, which influences the main redox processes that take place in the technological stages of the wine. The consecutive, parallel and spontaneous development of several redox processes and their impact on the quality, microbiological and crystalline stability of white wines were examined. The reduction of additive and subtractive technological interventions, of the amounts of adjuvants (sulphurous anhydride) is essential for the production of organic wines.
文摘玉米淀粉黄浆水是生产淀粉过程中排放的高浓度有机废水,以其作为Acetobacter xylinum DS398的基础培养基发酵细菌纤维素。采用Plackett-Burman设计和Box-Behnken响应面分析法对培养基成分进行优化,并对产物进行表征。以纤维素干重为响应值,从7个相关影响因素筛选出3个显著因子:蔗糖、磷酸二氢钾和乙醇。在此基础上,根据Box-Behnken响应面分析法确定以上三因素的最佳浓度。最优的玉米淀粉黄浆水培养基组分为:玉米黄浆水稀释比1∶4,蔗糖3.32 g/100 m L,CaCl_20.3 g/100 m L,KH_2PO_40.12 g/100 m L,Mg SO_40.05 g/100 m L,柠檬酸0.2 g/100 m L,乙醇1.50 m L/100 m L,细菌纤维素产量达到1.11 g/100 m L,为优化前的1.63倍。结果表明经优化后黄浆水培养基能够满足Acetobacter xylinum生长代谢的需要,细菌纤维素产量得到显著提高;同时傅立叶红外光谱图和场发射扫描电镜图显示产物是纯度较高的纤维素,微观结构与椰果相似。
文摘Vinegars are commonly used as food condiments and preservatives. Apple cider vinegar (ACV) is also used in the Ayurvedic pharmaceutical industry because of its medicinal properties. Since specifically selected starter cultures for commercial vinegar production are not readily available, apple juice supplemented with sugar is commonly inoculated with a microbiologically undefined culture obtained from the previous batch of ACV. The present work focuses on the isolation of yeasts and acetic acid bacteria from ACV and the preparation of a starter culture. ACV was produced in a bench scale bioreactor using a traditional fermentation process wherein an acetic acid concentration of 3.8% was obtained after three weeks. Several acetic acid bacteria (AAB) were isolated from ACV using selective media. Microscopy revealed the cultures to be gram negative to gram variable short rods. The growth pattern of the isolates on differential media and biochemical tests suggested the presence of Acetobacter and Gluconobacter species. Ten potent isolates were selected for starter culture preparation. Two consortia were formulated with five AAB isolates in each along with a yeast isolate and used for ACV production, wherein an acetic acid concentration of 4.2% - 4.9% was obtained in 10 - 12 days. Thus, these two starter cultures with locally isolated AAB can be used for the commercial production of apple cider vinegar.
