Microbial growth causes lamb spoilage.This study explored the spoilage ability of Latilactobacillus sakei,Serratia proteamaculans and Hafnia proteus in vacuum-packed raw lamb,including growth ability,degradation of pr...Microbial growth causes lamb spoilage.This study explored the spoilage ability of Latilactobacillus sakei,Serratia proteamaculans and Hafnia proteus in vacuum-packed raw lamb,including growth ability,degradation of protein and lipid,and change of volatile organic compounds(VOCs)profile,meanwhile screened the key VOCs produced by the targeted strains with meat background excluding,finally confirmed the volatile spoilage marker of vacuum-packaged lamb by comparing with our previous work.The results showed that L.sakei,S.proteamaculans and H.proteus had excellent growth ability.L.sakei inoculated group significantly reduced the pH value,showed higher trichloroacetic acid-soluble peptides content,and excellently degraded sarcoplasmic and myofibrillar proteins.About free amino acids,L.sakei significantly degraded serine,arginine and aspartic acid,while S.proteamaculans and H.proteus significantly degraded serine and lysine.In addition,L.sakei had the strongest effect on promoting free fatty acid production,followed by S.proteamaculans and finally H.proteus.Evaluating from various indicators,the co-culture of the three strains did not have any effect.The key volatiles produced by L.sakei were 1-hexanol,acetic acid and hexanoic acid,S.proteamaculans produced 1-hexanol and acetoin,and H.proteus produced 1-hexanol,acetic acid and acetoin.In the end,1-hexanol,hexanoic acid and acetoin were proven to be spoilage markers for vacuum-packaged and chilled lamb.This study can provide fundamental information for inhibiting and rapid identification of spoilage in vacuum-packaged lamb.展开更多
The biological hydrogen generating from fermentation of low-cost lignocellulosic feedstocks by hydrogen-producing bacteria has attracted many attentions in recent years. In the present investigation, ten hydrogen-prod...The biological hydrogen generating from fermentation of low-cost lignocellulosic feedstocks by hydrogen-producing bacteria has attracted many attentions in recent years. In the present investigation, ten hydrogen-producing bacteria were newly isolated from the intestine of wild common carp (</span><span style="font-family:Verdana;"><i>Cyprinus carpio</i></span><span style="font-family:Verdana;"> L.), and identified belonging to the genera of </span><i><span style="font-family:Verdana;">Enterobacter</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">Klebsiella</span></i><span style="font-family:Verdana;"> based on analysis of the 16S rDNA gene sequence and examination of the physiological and biochemical characteristics. All the isolates inherently owned the ability to metabolize xylose especially the cotton stalk hydrolysate for hydrogen production with hydrogen yield (HY) higher than 100 mL</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;">·</span></span><span></span><span></span><span style="font-family:""><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">. In particular, two isolates, WL1306 and WL1305 obtained higher HY, hydrogen production rate (HPR), and hydrogen production potential (HPP) using cotton stalk hydrolysate as sugar substrate than the mixed sugar of glucose & xylose, which obtained the HY of 249.5 ± 29.0, 397.0 ± 36.7 mL</span></span><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">, HPR of 10.4 ± 1.2, 16.5 ± 1.5 mL</span><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">h</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">, HPP of 19.5 ± 2.3, 31.0 ± 2.8 mL</span><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">g</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><sub><span style="font-family:Verdana;">sugar</span></sub><span style="font-family:Verdana;">, separately. The generation of soluble metabolites, such as the lactate, formate, acetate, succinate and ethanol reflected the mixed acid fermentation properties of the hydrogen production pathway.展开更多
基金supported by the China Agriculture Research System of Ministry of Finance of the People’s Republic of China(MOF)Ministry of Agriculture+1 种基金Rural Affairs of the People’s Republic of China(MARA)(CARS-38)S&T Program of Hebei(215A7101D).
文摘Microbial growth causes lamb spoilage.This study explored the spoilage ability of Latilactobacillus sakei,Serratia proteamaculans and Hafnia proteus in vacuum-packed raw lamb,including growth ability,degradation of protein and lipid,and change of volatile organic compounds(VOCs)profile,meanwhile screened the key VOCs produced by the targeted strains with meat background excluding,finally confirmed the volatile spoilage marker of vacuum-packaged lamb by comparing with our previous work.The results showed that L.sakei,S.proteamaculans and H.proteus had excellent growth ability.L.sakei inoculated group significantly reduced the pH value,showed higher trichloroacetic acid-soluble peptides content,and excellently degraded sarcoplasmic and myofibrillar proteins.About free amino acids,L.sakei significantly degraded serine,arginine and aspartic acid,while S.proteamaculans and H.proteus significantly degraded serine and lysine.In addition,L.sakei had the strongest effect on promoting free fatty acid production,followed by S.proteamaculans and finally H.proteus.Evaluating from various indicators,the co-culture of the three strains did not have any effect.The key volatiles produced by L.sakei were 1-hexanol,acetic acid and hexanoic acid,S.proteamaculans produced 1-hexanol and acetoin,and H.proteus produced 1-hexanol,acetic acid and acetoin.In the end,1-hexanol,hexanoic acid and acetoin were proven to be spoilage markers for vacuum-packaged and chilled lamb.This study can provide fundamental information for inhibiting and rapid identification of spoilage in vacuum-packaged lamb.
文摘The biological hydrogen generating from fermentation of low-cost lignocellulosic feedstocks by hydrogen-producing bacteria has attracted many attentions in recent years. In the present investigation, ten hydrogen-producing bacteria were newly isolated from the intestine of wild common carp (</span><span style="font-family:Verdana;"><i>Cyprinus carpio</i></span><span style="font-family:Verdana;"> L.), and identified belonging to the genera of </span><i><span style="font-family:Verdana;">Enterobacter</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">Klebsiella</span></i><span style="font-family:Verdana;"> based on analysis of the 16S rDNA gene sequence and examination of the physiological and biochemical characteristics. All the isolates inherently owned the ability to metabolize xylose especially the cotton stalk hydrolysate for hydrogen production with hydrogen yield (HY) higher than 100 mL</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;">·</span></span><span></span><span></span><span style="font-family:""><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">. In particular, two isolates, WL1306 and WL1305 obtained higher HY, hydrogen production rate (HPR), and hydrogen production potential (HPP) using cotton stalk hydrolysate as sugar substrate than the mixed sugar of glucose & xylose, which obtained the HY of 249.5 ± 29.0, 397.0 ± 36.7 mL</span></span><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">, HPR of 10.4 ± 1.2, 16.5 ± 1.5 mL</span><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">h</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">, HPP of 19.5 ± 2.3, 31.0 ± 2.8 mL</span><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">g</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><sub><span style="font-family:Verdana;">sugar</span></sub><span style="font-family:Verdana;">, separately. The generation of soluble metabolites, such as the lactate, formate, acetate, succinate and ethanol reflected the mixed acid fermentation properties of the hydrogen production pathway.
