OCFA production from Rhodococcus opacus PD630(R.opacus),which is a natural oleaginous bacterium,is limited by propionyl-CoA availability despite its potential for biofuel,nutritional,and pharmaceutical applications.Th...OCFA production from Rhodococcus opacus PD630(R.opacus),which is a natural oleaginous bacterium,is limited by propionyl-CoA availability despite its potential for biofuel,nutritional,and pharmaceutical applications.This study investigated the effects of enzymatically hydrolyzed black bean protein hydrolysates(BBPHs)as an alternative nitrogen source to stimulate OCFA biosynthesis.Among six hydrolysates,BBPH hydrolyzed by bromelain,flavourzym and Neutrase®markedly enhanced cell growth and lipid accumulation,achieving a 3-fold increase in OCFA content and elevating OCFA proportion to 30.78±0.97%of total fatty acids.The OCFA content has reached 1368.98±157.08 mg/L in BBPH-N.Metabolomic and lipidomic analyses revealed that BBPH supplementation significantly increased intracellular propionyl-CoA levels(750.29±45.00 ng/mg,compared with the 476.70±36.71 ng/mg of CN group),and modulated succinyl-CoA abundance,suggesting activation of the methyl malonyl-CoA pathway.A total of 69 OCFA-containing triglycerides and 17 diglycerides were identified,with TG 54:1(TG 17:0_19:0_18:1)emerging as a common lipid marker across BBPH supplementations.Moreover,BBPH hydrolyzed by Neutrase®enhanced the accumulation of C17-series fatty acids and improved nitrogen assimilation efficiency,as indicated by higher biomass and supernatant protein concentrations.Collectively,these results demonstrate that BBPH can reprogram carbon-nitrogen metabolism in R.opacus,promoting propionyl-CoA-derived OCFA synthesis.This work highlights a green and economically viable approach to microbial lipid production using agro-industrial byproducts,contributing to the advancement of circular bioeconomy strategies.展开更多
Plant-derived small peptides(PDSPs)have attracted increasing interest as functional,food-grade nitrogen sources.However,their regulatory effects on microbial lipid metabolism remain poorly understood.In this study,the...Plant-derived small peptides(PDSPs)have attracted increasing interest as functional,food-grade nitrogen sources.However,their regulatory effects on microbial lipid metabolism remain poorly understood.In this study,the effects of PDSPs(<1 kDa)from different protein sources on the growth performance,lipid accumulation,and odd-chain fatty acid(OCFA)biosynthesis of R.opacus were systematically investigated.Compared with inorganic nitrogen(urea)and free amino acid(Valine),PDSPs supplementation significantly enhanced biomass formation,with dry cell weight(DCW)increasing from 2.67±0.02 g/L in the control to 4.19±0.28 g/L in the black bean peptide-supplemented group.Total lipid content was markedly elevated by peptide nitrogen,reaching 65.62±2.01%of DCW,approximately 2.03-fold higher than that of the control(52.99±1.60%).Fatty acid analysis revealed a pronounced stimulation of OCFA biosynthesis,with total OCFA content increasing from 258.17±13.13 mg/L in the control to 953.42±62.73 mg/L in the black bean peptide-supplemented cultures.Lipidomic profiling revealed systematic remodeling of glycerolipid metabolism,marked by coordinated increases in diac-ylglycerols and triacylglycerols.Correlation analysis linked the amino acid composition of PDSPs to lipid accumulation efficiency and the production of OCFA.Overall,this study provides insights into how highly efficient peptide assimilation triggers early nitrogen exhaustion to redirect carbon flux towards lipid and OCFA biosynthesis,highlighting the unique potential of PDSPs as functional nitrogen substrates for microbial cell factories.展开更多
基金supported by the Research Program of State Key Laboratory of Food Science and Resources,Jiangnan University(No.SKLF-ZZA-202509)。
文摘OCFA production from Rhodococcus opacus PD630(R.opacus),which is a natural oleaginous bacterium,is limited by propionyl-CoA availability despite its potential for biofuel,nutritional,and pharmaceutical applications.This study investigated the effects of enzymatically hydrolyzed black bean protein hydrolysates(BBPHs)as an alternative nitrogen source to stimulate OCFA biosynthesis.Among six hydrolysates,BBPH hydrolyzed by bromelain,flavourzym and Neutrase®markedly enhanced cell growth and lipid accumulation,achieving a 3-fold increase in OCFA content and elevating OCFA proportion to 30.78±0.97%of total fatty acids.The OCFA content has reached 1368.98±157.08 mg/L in BBPH-N.Metabolomic and lipidomic analyses revealed that BBPH supplementation significantly increased intracellular propionyl-CoA levels(750.29±45.00 ng/mg,compared with the 476.70±36.71 ng/mg of CN group),and modulated succinyl-CoA abundance,suggesting activation of the methyl malonyl-CoA pathway.A total of 69 OCFA-containing triglycerides and 17 diglycerides were identified,with TG 54:1(TG 17:0_19:0_18:1)emerging as a common lipid marker across BBPH supplementations.Moreover,BBPH hydrolyzed by Neutrase®enhanced the accumulation of C17-series fatty acids and improved nitrogen assimilation efficiency,as indicated by higher biomass and supernatant protein concentrations.Collectively,these results demonstrate that BBPH can reprogram carbon-nitrogen metabolism in R.opacus,promoting propionyl-CoA-derived OCFA synthesis.This work highlights a green and economically viable approach to microbial lipid production using agro-industrial byproducts,contributing to the advancement of circular bioeconomy strategies.
基金supported by the Research Program of State Key Laboratory of Food Science and Resources,Jiangnan University(No.SKLF-ZZA-202509).
文摘Plant-derived small peptides(PDSPs)have attracted increasing interest as functional,food-grade nitrogen sources.However,their regulatory effects on microbial lipid metabolism remain poorly understood.In this study,the effects of PDSPs(<1 kDa)from different protein sources on the growth performance,lipid accumulation,and odd-chain fatty acid(OCFA)biosynthesis of R.opacus were systematically investigated.Compared with inorganic nitrogen(urea)and free amino acid(Valine),PDSPs supplementation significantly enhanced biomass formation,with dry cell weight(DCW)increasing from 2.67±0.02 g/L in the control to 4.19±0.28 g/L in the black bean peptide-supplemented group.Total lipid content was markedly elevated by peptide nitrogen,reaching 65.62±2.01%of DCW,approximately 2.03-fold higher than that of the control(52.99±1.60%).Fatty acid analysis revealed a pronounced stimulation of OCFA biosynthesis,with total OCFA content increasing from 258.17±13.13 mg/L in the control to 953.42±62.73 mg/L in the black bean peptide-supplemented cultures.Lipidomic profiling revealed systematic remodeling of glycerolipid metabolism,marked by coordinated increases in diac-ylglycerols and triacylglycerols.Correlation analysis linked the amino acid composition of PDSPs to lipid accumulation efficiency and the production of OCFA.Overall,this study provides insights into how highly efficient peptide assimilation triggers early nitrogen exhaustion to redirect carbon flux towards lipid and OCFA biosynthesis,highlighting the unique potential of PDSPs as functional nitrogen substrates for microbial cell factories.
