Bacillus subtilis is a representative probiotic widely used in food, medicine, livestock and other industries. In this experiment a strain of Bacillus subtilis was isolated and identified, and its ability to degrade c...Bacillus subtilis is a representative probiotic widely used in food, medicine, livestock and other industries. In this experiment a strain of Bacillus subtilis was isolated and identified, and its ability to degrade cellulose was also measured. The results showed that Bacillus subtilis had strong capacity to degrade cellulose(62.3% was degraded) and weak capacity to degrade hemicellulose(17.2% was degraded), while it could hardly degrade lignin. The total protein amount in the fermentation medium with cellulose-rich substrate reached by 9.4% after Bacillus subtilis fermentation, compared with that without cellulose-rich substrate. Furthermore, the amounts of Met, Lys and Leu reached by 31.4%, 42.2% and 4.9%, respectively. At 36 h of fermentation, the activity of cellulase reached the highest, and at this time the activity of the enzyme was obtained at 7.19 U · mL-1. The mRNA expression level of the cellulase gene was detected by qPCR, and the experimental group with cellulose substrate was about 2.5 times more than that of the non-cellulose substrate control group. These above results demonstrated that this strain of Bacillus subtilis had a strong ability to degrade cellulose, and synthesize more proteins and restrictive essential amino acids. This study revealed that Bacillus subtilis was a new alternative to ferment cellulose substrates to produce commercial feed or feed additives.展开更多
Bacillus lincheniformis is a representative probiotic, widely used in food, medicine and livestock industries and other industries. In this experiment, a strain of Bacillus lincheniformis was isolated and identified, ...Bacillus lincheniformis is a representative probiotic, widely used in food, medicine and livestock industries and other industries. In this experiment, a strain of Bacillus lincheniformis was isolated and identified, which was used to ferment celluloserich substrate. The effects were analyzed. The experimental results showed that Bacillus lincheniformis had the capacity to degrade cellulose(32.8% was degraded) and less capacity to degrade hemicellulose(7.9% was degraded), which could not degrade ligin. The total protein contents in the products fermented by Bacillus lincheniformis with cellulose-rich substrate riched by 11.6%, compared with the fermented products with no cellulose-rich substrate, furthermore, the contents of Met, Lys and Leu riched by 14%, 17.5% and 4.1%, respectively. These results showed that Bacillus lincheniformis had the ability to degrade cellulose and it provided experimental data for further utilization.展开更多
基金Supported by the Key Applied Technology Research and Development Program of Heilongjiang Province(GA15B203)Student Innovation and Pioneer Training Program(SIPT)of Northeast Agricultural University(SIPT,201610224153)
文摘Bacillus subtilis is a representative probiotic widely used in food, medicine, livestock and other industries. In this experiment a strain of Bacillus subtilis was isolated and identified, and its ability to degrade cellulose was also measured. The results showed that Bacillus subtilis had strong capacity to degrade cellulose(62.3% was degraded) and weak capacity to degrade hemicellulose(17.2% was degraded), while it could hardly degrade lignin. The total protein amount in the fermentation medium with cellulose-rich substrate reached by 9.4% after Bacillus subtilis fermentation, compared with that without cellulose-rich substrate. Furthermore, the amounts of Met, Lys and Leu reached by 31.4%, 42.2% and 4.9%, respectively. At 36 h of fermentation, the activity of cellulase reached the highest, and at this time the activity of the enzyme was obtained at 7.19 U · mL-1. The mRNA expression level of the cellulase gene was detected by qPCR, and the experimental group with cellulose substrate was about 2.5 times more than that of the non-cellulose substrate control group. These above results demonstrated that this strain of Bacillus subtilis had a strong ability to degrade cellulose, and synthesize more proteins and restrictive essential amino acids. This study revealed that Bacillus subtilis was a new alternative to ferment cellulose substrates to produce commercial feed or feed additives.
基金Supported by the Key Applied Technology Research and Development Program of Heilongjiang Province(GA15B203)Student Innovation and Pioneer Training Program(SIPT)of Northeast Agricultural University(SIPT,201610224153)
文摘Bacillus lincheniformis is a representative probiotic, widely used in food, medicine and livestock industries and other industries. In this experiment, a strain of Bacillus lincheniformis was isolated and identified, which was used to ferment celluloserich substrate. The effects were analyzed. The experimental results showed that Bacillus lincheniformis had the capacity to degrade cellulose(32.8% was degraded) and less capacity to degrade hemicellulose(7.9% was degraded), which could not degrade ligin. The total protein contents in the products fermented by Bacillus lincheniformis with cellulose-rich substrate riched by 11.6%, compared with the fermented products with no cellulose-rich substrate, furthermore, the contents of Met, Lys and Leu riched by 14%, 17.5% and 4.1%, respectively. These results showed that Bacillus lincheniformis had the ability to degrade cellulose and it provided experimental data for further utilization.
