Camellia oleifera cake(COC), a nutrient-rich by-product of tea oil extraction, holds promise as a high-quality protein source but is limited in feed applications due to anti-nutritional factors, mainly tea saponins an...Camellia oleifera cake(COC), a nutrient-rich by-product of tea oil extraction, holds promise as a high-quality protein source but is limited in feed applications due to anti-nutritional factors, mainly tea saponins and crude fiber. This study employed solid-state fermentation using a compound microbial agent combined with cellulase to enhance COC's palatability and nutritional value. Single-strain fermentation identified Lactiplantibacillus plantarum as most effective in degrading tea saponins(46.0%) without reducing crude fiber. Optimal conditions were 0.1% inoculum, 48 h at 37 ℃, with 20% sugar. For cellulase hydrolysis, the best parameters were: 50 U/g enzyme, 50 ℃, 8 h, using 40-mesh sieved substrate. Combined fermentation began with enzymatic treatment followed by inoculation with a 1: 1: 1: 1: 1: 1 mixture of Saccharomyces cerevisiae(two strains), Lactiplantibacillus plantarum, Bacillus subtilis, Bacillus coagulans, and Lactobacillus acidophilus. The optimized conditions(0.1% inoculum, 7 days, 37 ℃, 20% sugar, 50% moisture) significantly reduced anti-nutritional components and improved protein content, indicating the potential of fermented COC as a viable feed ingredient.展开更多
Paddy fields are considered a major source of methane(CH_4)emissions.Aerobic irrigation methods have proven to be efficacious in mitigating CH_4 emissions in paddy cultivation.The promising role of compound microbial ...Paddy fields are considered a major source of methane(CH_4)emissions.Aerobic irrigation methods have proven to be efficacious in mitigating CH_4 emissions in paddy cultivation.The promising role of compound microbial agents in refining the rhizospheric ecosystem suggests their potential as novel agents in reducing CH_4 emissions from paddy fields.To explore a new method of using compound microbial agents to reduce CH_4 emissions,we conducted pot and field experiments over the period of 2022-2023.We measured CH_4 flux,the redox potential(Eh)of the soil,the concentration of dissolved oxygen(DO)in the floodwater,and the gene abundance of both methanogens(mcr A)and methanotrophs(pmo A).The results showed that the application of the compound microbial agent led to a significant increase in the DO levels within the floodwater and an increase of 9.26%to 35.01%in the Eh of the tillage soil.Furthermore,the abundance of pmo A increased by 31.20%,while the mcr A/pmo A ratio decreased by 25.96%at the maximum tillering stage.Applying 45-75 kg/hm^(2) of the compound microbial agent before transplanting resulted in a reduction of cumulative CH_4 emissions from paddy fields by 17.49%in single-cropped rice and 43.54%to 50.27%in double-cropped late rice during the tillering stage.Correlation analysis indicated that CH_4 flux was significantly negatively correlated with pmo A gene abundance and soil Eh,and positively related to the mcr A/pmo A ratio.Additionally,soil Eh was significantly positively correlated with pmo A gene abundance,suggesting that paddy soil Eh indirectly affected CH_4 flux by influencing the pmo A gene abundance.In conclusion,the pre-planting application of the compound microbial agent at a rate of 45-75 kg/hm^(2) can enhance the Eh in the rhizosphere and increase the abundance of the pmo A gene,thereby reducing CH_4 emissions from paddy fields during the tillering stage of rice growth.展开更多
基金supported the Key Area Research and Development Program of Guangdong Province (2023B0202070002)the Agricultural Science and Technology Innovation Project of the Chinese academy of Agricultural Sciences (CAAS-ASTIP-2021-OCRI)+1 种基金Earmarked Fund for Agriculture Research System of China (CARS-14)the Innovation Group Project of Hubei Province (2023AFA042)。
文摘Camellia oleifera cake(COC), a nutrient-rich by-product of tea oil extraction, holds promise as a high-quality protein source but is limited in feed applications due to anti-nutritional factors, mainly tea saponins and crude fiber. This study employed solid-state fermentation using a compound microbial agent combined with cellulase to enhance COC's palatability and nutritional value. Single-strain fermentation identified Lactiplantibacillus plantarum as most effective in degrading tea saponins(46.0%) without reducing crude fiber. Optimal conditions were 0.1% inoculum, 48 h at 37 ℃, with 20% sugar. For cellulase hydrolysis, the best parameters were: 50 U/g enzyme, 50 ℃, 8 h, using 40-mesh sieved substrate. Combined fermentation began with enzymatic treatment followed by inoculation with a 1: 1: 1: 1: 1: 1 mixture of Saccharomyces cerevisiae(two strains), Lactiplantibacillus plantarum, Bacillus subtilis, Bacillus coagulans, and Lactobacillus acidophilus. The optimized conditions(0.1% inoculum, 7 days, 37 ℃, 20% sugar, 50% moisture) significantly reduced anti-nutritional components and improved protein content, indicating the potential of fermented COC as a viable feed ingredient.
基金supported by the Zhejiang‘Ten Thousand Talents’Plan Science and Technology Innovation Leading Talent Project,China (Grant No.2020R52035)the National Rice Industry Technology System of China (Grant No.CARS-01-31)the Agricultural Science and Technology Innovation Program,China (Grant No.CAAS-ZDRW202001)。
文摘Paddy fields are considered a major source of methane(CH_4)emissions.Aerobic irrigation methods have proven to be efficacious in mitigating CH_4 emissions in paddy cultivation.The promising role of compound microbial agents in refining the rhizospheric ecosystem suggests their potential as novel agents in reducing CH_4 emissions from paddy fields.To explore a new method of using compound microbial agents to reduce CH_4 emissions,we conducted pot and field experiments over the period of 2022-2023.We measured CH_4 flux,the redox potential(Eh)of the soil,the concentration of dissolved oxygen(DO)in the floodwater,and the gene abundance of both methanogens(mcr A)and methanotrophs(pmo A).The results showed that the application of the compound microbial agent led to a significant increase in the DO levels within the floodwater and an increase of 9.26%to 35.01%in the Eh of the tillage soil.Furthermore,the abundance of pmo A increased by 31.20%,while the mcr A/pmo A ratio decreased by 25.96%at the maximum tillering stage.Applying 45-75 kg/hm^(2) of the compound microbial agent before transplanting resulted in a reduction of cumulative CH_4 emissions from paddy fields by 17.49%in single-cropped rice and 43.54%to 50.27%in double-cropped late rice during the tillering stage.Correlation analysis indicated that CH_4 flux was significantly negatively correlated with pmo A gene abundance and soil Eh,and positively related to the mcr A/pmo A ratio.Additionally,soil Eh was significantly positively correlated with pmo A gene abundance,suggesting that paddy soil Eh indirectly affected CH_4 flux by influencing the pmo A gene abundance.In conclusion,the pre-planting application of the compound microbial agent at a rate of 45-75 kg/hm^(2) can enhance the Eh in the rhizosphere and increase the abundance of the pmo A gene,thereby reducing CH_4 emissions from paddy fields during the tillering stage of rice growth.
