Isu N R, Njoku H O
Microbiology and Biotechnology Unit, School of Biological Sciences, Abia State University, Uturu.
Plant Foods Hum Nutr. 1997;51(2):145-57. doi: 10.1023/a:1007906413195.
The microorganisms associated with fermented African oil bean (Pentaclethra macrophylla Bentham) seed during ugba production was studied. Only bacteria were isolated from the ugba samples used. Although the bacteria included Bacillus spp., Lactobacillus spp., Staphylococcus spp., Micrococcus spp. and members of the family Enterobacteriaceae, only the Bacillus spp. were found to ferment African oil bean seeds to ugba. Bacillus spp. were the predominant microorganisms present, constituting over 95% of the total microbial population density. An increase in the number of Bacillus cells of about 2 log units daily, which attained a maximum density of log10 9.00 - log10 11.90 cfu/g after 3 days was observed. Contrarily, the Lactobacillus spp. increased minimally and attained a maximum value of log10 4.20 - log10 6.35 cfu/g within the same period. The Staphylococcus spp., Micrococcus spp. and the members of the family Enterobacteriaceae remained fairly steady in number for 24h, increased slightly till the 3rd day followed by exponential increases which attained maximum values of between log10 9.20 - log10 11.00, about the 7th day. Bacillus spp. cells also had the highest protease activities which were significantly (p < 0.05) higher than the values for the other bacterial isolates. The Bacillus spp. responsible for the fermentation of African oil bean seeds to ugba were identified as Bacillus coagulans, B. macerans, B. megaterium, B. pumilis and B. subtilis.
对乌格巴(ugba)生产过程中与发酵非洲油豆(Pentaclethra macrophylla Bentham)种子相关的微生物进行了研究。仅从所使用的乌格巴样品中分离出了细菌。尽管这些细菌包括芽孢杆菌属(Bacillus spp.)、乳杆菌属(Lactobacillus spp.)、葡萄球菌属(Staphylococcus spp.)、微球菌属(Micrococcus spp.)和肠杆菌科(Enterobacteriaceae)的成员,但发现只有芽孢杆菌属能将非洲油豆种子发酵成乌格巴。芽孢杆菌属是存在的主要微生物,占微生物总种群密度的95%以上。观察到芽孢杆菌细胞数量每天增加约2个对数单位,3天后达到最大密度log10 9.00 - log10 11.90 cfu/g。相反,乳杆菌属增加极少,在同一时期内达到最大值log10 4.20 - log10 6.35 cfu/g。葡萄球菌属、微球菌属和肠杆菌科的成员数量在24小时内保持相当稳定,到第3天略有增加,随后呈指数增长,在大约第7天达到最大值log10 9.20 - log10 11.00。芽孢杆菌属细胞也具有最高的蛋白酶活性,显著(p < 0.05)高于其他细菌分离株的值。负责将非洲油豆种子发酵成乌格巴的芽孢杆菌属被鉴定为凝结芽孢杆菌(Bacillus coagulans)、浸麻芽孢杆菌(B. macerans)、巨大芽孢杆菌(B. megaterium)、短小芽孢杆菌(B. pumilis)和枯草芽孢杆菌(B. subtilis)。