Lactic acid bacteria have not only been used to produce various kinds of fermented food, but also used as probiotic products. As lactic acid bacterial group was consisted from diverse genera, a simple inspection metho...Lactic acid bacteria have not only been used to produce various kinds of fermented food, but also used as probiotic products. As lactic acid bacterial group was consisted from diverse genera, a simple inspection method by which numbers and contained microorganisms could be automatically analyzed without any preliminary information was required to use them more effectively. In this manuscript, lactic acid bacterial groups in commercial products of kimuchi, komekouji-miso, and yoghurt were identified and enumerated by our newly developed method [1]-[3], to evaluate whether the method could be used as an inspection method of various food samples. In kimuchi, numerically dominant bacteria were Lactobacillus sakei, and L. casei (1.4 × 104 MPN g<sup>-1</sup>) and Leuconostoc spp. (l.4 × 104 MPN). In kouji-miso, numerically dominant bacteria was Bacillus spp. (3 × 103 MPN), which mainly included B. subtilis group and B. cereus group. Lactic acid bacteria such as Lactobacillus spp., or Lactococcus spp., included in the komekouji-miso, could be enumerated after 3 days incubation (1.24 × 104 MPN), but not detected after 7 days incubation. In yoghurt A and C, Lactococcus lactis was detected as numerically dominant lactic acid bacteria (3.0 × 105 MPN). In yoghurt B, Lactobacillus spp., or Lactococcus spp., was detected not only by a culturebased method but also by an unculture-based method, although there was a difference between the both estimated numbers. The present results suggested that the method might become useful as a simple inspection method of food microorganisms, because time and labor of the analysis could be reduced by using an unculture-based method and MCE-202 MultiNA. In this study, Bifidobacteriium spp. was not detected in B and C yoghurt, in spite of indicating their existence, and numbers of lactic acid bacteria were lower than the level of the daily product regulation, because 16S rDNA of Bifidobacteriium spp. might not be amplified by the used PCR condition. The PCR condition must be changed so as to amplify Bifidobacterium spp., before the method will be used as an inspection method for lactic acid bacteria.展开更多
The influence of medium ingredients on extracellular dextransucrase production by a new bacterial strain Weissella confusa Cab3 (Genbank Accession Number JX649223) was evaluated using fractional factorial design of Ta...The influence of medium ingredients on extracellular dextransucrase production by a new bacterial strain Weissella confusa Cab3 (Genbank Accession Number JX649223) was evaluated using fractional factorial design of Taguchi's orthogonal array. Four metabolism influencing factors viz. sucrose, yeast extract, K2HPO4 and Tween80 were selected to optimize dextransucrase production by W. confusa Cab3 using fractional factorial design of Taguchi methodology. Based on the influence of interaction components of fermentation, least significant factors of individual level have higher interaction severity index and vice versa for enzyme production from Weissella confusa Cab3. Sucrose and yeast extract were found to be the most significant factors which positively influenced the dextransucrase production. The optimized medium composition consisted of sucrose—5%;yeast extract—2%;K2HPO4—1.0%;Tween80—0.5%, based on Taguchi orthogonal array method. The optimized composition gave an experimental value of dextransucrase activity of 17.9 U/ml at shake flask level which corresponded well with the predicted value of 17.54 U/ml by the model. The optimized medium by Taguchi method gave significant (3 fold) enhancement of dextransucrase activity as compared to unoptimised enzyme activity of 6.0 U/ml. The dextransucrase production was scaled up in lab scale bioreactor resulting in further enhancement of enzyme activity (22.0 U/ml).展开更多
为促进花生粕的综合利用,以13株乳酸菌发酵花生粕乳,采用逼近理想解排序(TOPSIS)法分别从酸度、黏度、氨基酸态氮浓度、持水力、活菌数和感官属性等方面进行综合评价,探究乳酸菌在花生粕乳中的发酵性能。结果表明,植物乳杆菌植物亚种(L6...为促进花生粕的综合利用,以13株乳酸菌发酵花生粕乳,采用逼近理想解排序(TOPSIS)法分别从酸度、黏度、氨基酸态氮浓度、持水力、活菌数和感官属性等方面进行综合评价,探究乳酸菌在花生粕乳中的发酵性能。结果表明,植物乳杆菌植物亚种(L6)的产酸速率最高,达到9.57°T/h,其次是植物乳杆菌(X2),为9.26°T/h。植物乳杆菌(X2)和副干酪乳杆菌(X5)的后酸化能力较弱,贮藏期间酸度变化量分别为10.84°T和9.58°T,且这两株菌产氨基酸态氮浓度较高,分别为589.87μg/mL和562.28μg/mL。嗜热链球菌(S2)的产黏能力和持水力最强,分别为1227.33 mPa·s和42.62%,且其综合感官评分最高,为89.75分。发酵乳杆菌(FYa1)和植物乳杆菌(MDb2)的活菌数最高,分别为8.89 lg CFU/mL和8.80 lg CFU/mL。采用TOPSIS法综合评价,得出嗜热链球菌(S2)为综合发酵性能较优良的菌株,以其为核心菌株辅以乳酸杆菌作为发酵剂应用于花生粕乳的发酵,可为花生粕乳发酵产品的开发提供有效路径。展开更多
文摘Lactic acid bacteria have not only been used to produce various kinds of fermented food, but also used as probiotic products. As lactic acid bacterial group was consisted from diverse genera, a simple inspection method by which numbers and contained microorganisms could be automatically analyzed without any preliminary information was required to use them more effectively. In this manuscript, lactic acid bacterial groups in commercial products of kimuchi, komekouji-miso, and yoghurt were identified and enumerated by our newly developed method [1]-[3], to evaluate whether the method could be used as an inspection method of various food samples. In kimuchi, numerically dominant bacteria were Lactobacillus sakei, and L. casei (1.4 × 104 MPN g<sup>-1</sup>) and Leuconostoc spp. (l.4 × 104 MPN). In kouji-miso, numerically dominant bacteria was Bacillus spp. (3 × 103 MPN), which mainly included B. subtilis group and B. cereus group. Lactic acid bacteria such as Lactobacillus spp., or Lactococcus spp., included in the komekouji-miso, could be enumerated after 3 days incubation (1.24 × 104 MPN), but not detected after 7 days incubation. In yoghurt A and C, Lactococcus lactis was detected as numerically dominant lactic acid bacteria (3.0 × 105 MPN). In yoghurt B, Lactobacillus spp., or Lactococcus spp., was detected not only by a culturebased method but also by an unculture-based method, although there was a difference between the both estimated numbers. The present results suggested that the method might become useful as a simple inspection method of food microorganisms, because time and labor of the analysis could be reduced by using an unculture-based method and MCE-202 MultiNA. In this study, Bifidobacteriium spp. was not detected in B and C yoghurt, in spite of indicating their existence, and numbers of lactic acid bacteria were lower than the level of the daily product regulation, because 16S rDNA of Bifidobacteriium spp. might not be amplified by the used PCR condition. The PCR condition must be changed so as to amplify Bifidobacterium spp., before the method will be used as an inspection method for lactic acid bacteria.
文摘The influence of medium ingredients on extracellular dextransucrase production by a new bacterial strain Weissella confusa Cab3 (Genbank Accession Number JX649223) was evaluated using fractional factorial design of Taguchi's orthogonal array. Four metabolism influencing factors viz. sucrose, yeast extract, K2HPO4 and Tween80 were selected to optimize dextransucrase production by W. confusa Cab3 using fractional factorial design of Taguchi methodology. Based on the influence of interaction components of fermentation, least significant factors of individual level have higher interaction severity index and vice versa for enzyme production from Weissella confusa Cab3. Sucrose and yeast extract were found to be the most significant factors which positively influenced the dextransucrase production. The optimized medium composition consisted of sucrose—5%;yeast extract—2%;K2HPO4—1.0%;Tween80—0.5%, based on Taguchi orthogonal array method. The optimized composition gave an experimental value of dextransucrase activity of 17.9 U/ml at shake flask level which corresponded well with the predicted value of 17.54 U/ml by the model. The optimized medium by Taguchi method gave significant (3 fold) enhancement of dextransucrase activity as compared to unoptimised enzyme activity of 6.0 U/ml. The dextransucrase production was scaled up in lab scale bioreactor resulting in further enhancement of enzyme activity (22.0 U/ml).
文摘为促进花生粕的综合利用,以13株乳酸菌发酵花生粕乳,采用逼近理想解排序(TOPSIS)法分别从酸度、黏度、氨基酸态氮浓度、持水力、活菌数和感官属性等方面进行综合评价,探究乳酸菌在花生粕乳中的发酵性能。结果表明,植物乳杆菌植物亚种(L6)的产酸速率最高,达到9.57°T/h,其次是植物乳杆菌(X2),为9.26°T/h。植物乳杆菌(X2)和副干酪乳杆菌(X5)的后酸化能力较弱,贮藏期间酸度变化量分别为10.84°T和9.58°T,且这两株菌产氨基酸态氮浓度较高,分别为589.87μg/mL和562.28μg/mL。嗜热链球菌(S2)的产黏能力和持水力最强,分别为1227.33 mPa·s和42.62%,且其综合感官评分最高,为89.75分。发酵乳杆菌(FYa1)和植物乳杆菌(MDb2)的活菌数最高,分别为8.89 lg CFU/mL和8.80 lg CFU/mL。采用TOPSIS法综合评价,得出嗜热链球菌(S2)为综合发酵性能较优良的菌株,以其为核心菌株辅以乳酸杆菌作为发酵剂应用于花生粕乳的发酵,可为花生粕乳发酵产品的开发提供有效路径。
