Catherine M Spirito, Timo N Lucas, Sascha Patz, Byoung Seung Jeon, Jeffrey J Werner, Lauren H Trondsen, Juan J Guzman, Daniel H Huson, Largus T Angenent
{"title":"在线产品提取反应器中正辛酸酯和正己酸酯生产微生物群的变异性。","authors":"Catherine M Spirito, Timo N Lucas, Sascha Patz, Byoung Seung Jeon, Jeffrey J Werner, Lauren H Trondsen, Juan J Guzman, Daniel H Huson, Largus T Angenent","doi":"10.1128/msystems.00416-24","DOIUrl":null,"url":null,"abstract":"<p><p>Medium-chain carboxylates (MCCs) are used in various industrial applications. These chemicals are typically extracted from palm oil, which is deemed not sustainable. Recent research has focused on microbial chain elongation using reactors to produce MCCs, such as <i>n</i>-caproate (C6) and <i>n</i>-caprylate (C8), from organic substrates such as wastes. Even though the production of <i>n</i>-caproate is relatively well-characterized, bacteria and metabolic pathways that are responsible for <i>n</i>-caprylate production are not. Here, three 5 L reactors with continuous membrane-based liquid-liquid extraction (i.e., pertraction) were fed ethanol and acetate and operated for an operating period of 234 days with different operating conditions. Metagenomic and metaproteomic analyses were employed. <i>n</i>-Caprylate production rates and reactor microbiomes differed between reactors even when operated similarly due to differences in H<sub>2</sub> and O<sub>2</sub> between the reactors. The complete reverse β-oxidation (RBOX) pathway was present and expressed by several bacterial species in the <i>Clostridia</i> class. Several <i>Oscillibacter</i> spp., including <i>Oscillibacter valericigenes</i>, were positively correlated with <i>n</i>-caprylate production rates, while <i>Clostridium kluyveri</i> was positively correlated with <i>n</i>-caproate production. <i>Pseudoclavibacter caeni</i>, which is a strictly aerobic bacterium, was abundant across all the operating periods, regardless of <i>n</i>-caprylate production rates. This study provides insight into microbiota that are associated with <i>n</i>-caprylate production in open-culture reactors and provides ideas for further work.IMPORTANCEMicrobial chain elongation pathways in open-culture biotechnology systems can be utilized to convert organic waste and industrial side streams into valuable industrial chemicals. Here, we investigated the microbiota and metabolic pathways that produce medium-chain carboxylates (MCCs), including <i>n</i>-caproate (C6) and <i>n</i>-caprylate (C8), in reactors with in-line product extraction. Although the reactors in this study were operated similarly, different microbial communities dominated and were responsible for chain elongation. We found that different microbiota were responsible for <i>n</i>-caproate or <i>n</i>-caprylate production, and this can inform engineers on how to operate the systems better. We also observed which changes in operating conditions steered the production toward and away from <i>n</i>-caprylate, but more work is necessary to ascertain a mechanistic understanding that could be predictive. This study provides pertinent research questions for future work.</p>","PeriodicalId":18819,"journal":{"name":"mSystems","volume":null,"pages":null},"PeriodicalIF":5.0000,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11334527/pdf/","citationCount":"0","resultStr":"{\"title\":\"Variability in <i>n</i>-caprylate and <i>n</i>-caproate producing microbiomes in reactors with in-line product extraction.\",\"authors\":\"Catherine M Spirito, Timo N Lucas, Sascha Patz, Byoung Seung Jeon, Jeffrey J Werner, Lauren H Trondsen, Juan J Guzman, Daniel H Huson, Largus T Angenent\",\"doi\":\"10.1128/msystems.00416-24\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Medium-chain carboxylates (MCCs) are used in various industrial applications. These chemicals are typically extracted from palm oil, which is deemed not sustainable. Recent research has focused on microbial chain elongation using reactors to produce MCCs, such as <i>n</i>-caproate (C6) and <i>n</i>-caprylate (C8), from organic substrates such as wastes. Even though the production of <i>n</i>-caproate is relatively well-characterized, bacteria and metabolic pathways that are responsible for <i>n</i>-caprylate production are not. Here, three 5 L reactors with continuous membrane-based liquid-liquid extraction (i.e., pertraction) were fed ethanol and acetate and operated for an operating period of 234 days with different operating conditions. Metagenomic and metaproteomic analyses were employed. <i>n</i>-Caprylate production rates and reactor microbiomes differed between reactors even when operated similarly due to differences in H<sub>2</sub> and O<sub>2</sub> between the reactors. The complete reverse β-oxidation (RBOX) pathway was present and expressed by several bacterial species in the <i>Clostridia</i> class. Several <i>Oscillibacter</i> spp., including <i>Oscillibacter valericigenes</i>, were positively correlated with <i>n</i>-caprylate production rates, while <i>Clostridium kluyveri</i> was positively correlated with <i>n</i>-caproate production. <i>Pseudoclavibacter caeni</i>, which is a strictly aerobic bacterium, was abundant across all the operating periods, regardless of <i>n</i>-caprylate production rates. This study provides insight into microbiota that are associated with <i>n</i>-caprylate production in open-culture reactors and provides ideas for further work.IMPORTANCEMicrobial chain elongation pathways in open-culture biotechnology systems can be utilized to convert organic waste and industrial side streams into valuable industrial chemicals. Here, we investigated the microbiota and metabolic pathways that produce medium-chain carboxylates (MCCs), including <i>n</i>-caproate (C6) and <i>n</i>-caprylate (C8), in reactors with in-line product extraction. Although the reactors in this study were operated similarly, different microbial communities dominated and were responsible for chain elongation. We found that different microbiota were responsible for <i>n</i>-caproate or <i>n</i>-caprylate production, and this can inform engineers on how to operate the systems better. We also observed which changes in operating conditions steered the production toward and away from <i>n</i>-caprylate, but more work is necessary to ascertain a mechanistic understanding that could be predictive. 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Variability in n-caprylate and n-caproate producing microbiomes in reactors with in-line product extraction.
Medium-chain carboxylates (MCCs) are used in various industrial applications. These chemicals are typically extracted from palm oil, which is deemed not sustainable. Recent research has focused on microbial chain elongation using reactors to produce MCCs, such as n-caproate (C6) and n-caprylate (C8), from organic substrates such as wastes. Even though the production of n-caproate is relatively well-characterized, bacteria and metabolic pathways that are responsible for n-caprylate production are not. Here, three 5 L reactors with continuous membrane-based liquid-liquid extraction (i.e., pertraction) were fed ethanol and acetate and operated for an operating period of 234 days with different operating conditions. Metagenomic and metaproteomic analyses were employed. n-Caprylate production rates and reactor microbiomes differed between reactors even when operated similarly due to differences in H2 and O2 between the reactors. The complete reverse β-oxidation (RBOX) pathway was present and expressed by several bacterial species in the Clostridia class. Several Oscillibacter spp., including Oscillibacter valericigenes, were positively correlated with n-caprylate production rates, while Clostridium kluyveri was positively correlated with n-caproate production. Pseudoclavibacter caeni, which is a strictly aerobic bacterium, was abundant across all the operating periods, regardless of n-caprylate production rates. This study provides insight into microbiota that are associated with n-caprylate production in open-culture reactors and provides ideas for further work.IMPORTANCEMicrobial chain elongation pathways in open-culture biotechnology systems can be utilized to convert organic waste and industrial side streams into valuable industrial chemicals. Here, we investigated the microbiota and metabolic pathways that produce medium-chain carboxylates (MCCs), including n-caproate (C6) and n-caprylate (C8), in reactors with in-line product extraction. Although the reactors in this study were operated similarly, different microbial communities dominated and were responsible for chain elongation. We found that different microbiota were responsible for n-caproate or n-caprylate production, and this can inform engineers on how to operate the systems better. We also observed which changes in operating conditions steered the production toward and away from n-caprylate, but more work is necessary to ascertain a mechanistic understanding that could be predictive. This study provides pertinent research questions for future work.
mSystemsBiochemistry, Genetics and Molecular Biology-Biochemistry
CiteScore
10.50
自引率
3.10%
发文量
308
审稿时长
13 weeks
期刊介绍:
mSystems™ will publish preeminent work that stems from applying technologies for high-throughput analyses to achieve insights into the metabolic and regulatory systems at the scale of both the single cell and microbial communities. The scope of mSystems™ encompasses all important biological and biochemical findings drawn from analyses of large data sets, as well as new computational approaches for deriving these insights. mSystems™ will welcome submissions from researchers who focus on the microbiome, genomics, metagenomics, transcriptomics, metabolomics, proteomics, glycomics, bioinformatics, and computational microbiology. mSystems™ will provide streamlined decisions, while carrying on ASM''s tradition of rigorous peer review.