scholarly journals Genome-wide transcriptomic analysis of n-caproic acid production in Ruminococcaceae bacterium CPB6 with lactate supplementation

2020 ◽  
Author(s):  
Yong Tao ◽  
Shaowen Lu ◽  
Yi Wang ◽  
Cuicui Wei ◽  
Hong Jin ◽  
...  

Abstract Background n-Caproic acid (CA) is gaining increased attention due to its high value as a chemical feedstock. Ruminococcaceae bacterium strain CPB6 is an anaerobic mesophilic bacterium that is highly prolific in its ability to perform chain elongation of lactate to CA. However, little is known about the genome-wide transcriptional analysis of strain CPB6 for CA production triggered by the supplementation of exogenous lactate. Results In this study, 0.5% lactate was supplemented into the fermentation with Ruminococcaceae bacterium CPB6 for CA production. Compared to the control (without lactate supplementation), lactate supplementation led to earlier CA production and higher final CA titer and productivity. Transcriptional analysis was carried out using RNA-Seq for the culture with and without lactate supplementation (two groups) at growth and stationary phases, respectively. It has been indicated that 295 genes whose changes in expression patterns were substrate and/or growth dependent. These genes cover crucial functional categories. Specifically, 5 genes responsible for the reverse β-oxidation pathway, 11 genes encoding ATP-binding cassette (ABC) transporters, 6 genes encoding substrate-binding protein (SBP) and 4 genes encoding phosphotransferase system (PTS) transporters were strikingly upregulated in response to the addition of lactate. These genes would be candidates for future studies aiming at understanding the regulatory mechanism of lactate conversion into CA, as well as for the improvement of CA production in strain CPB6. Conclusions This study suggested that lactate supplementation can promote CA production by altering the expression patterns of genes involved in the essential metabolic pathways, such as central pyruvate metabolism, the reverse β-oxidation pathway, ABC and PTS transports. The findings presented herein reveal unique insights into the biomolecular effects of lactate on CA production at the gene transcriptional level.

2020 ◽  
Author(s):  
YONG TAO ◽  
Shaowen Lu ◽  
Yi Wang ◽  
Cuicui Wei

Abstract Background: n-Caproic acid (CA) is gaining increased attention due to its high value as a chemical feedstock. Our recent studies have demonstrated that lactate can be an attractive energy substrate for the production of CA. However, little is known about the potential molecular mechanism for CA production triggered by the supplementation of exogenous lactate at the gene transcriptional level. Results: 5% lactate was supplemented into the fermentation with Ruminococcaceae bacterium CPB6 for CA production. Results showed that lactate supplementation led to earlier CA production and higher final CA titer and productivity. Transcriptional analysis was carried out using RNA-Seq for the culture with lactate supplementation compared to the control (without lactate supplementation). It has been indicated that there were only 34 differentially expressed genes (DEGs) between the two groups at the exponential phase, of which 15 were upregulated, and 19 were downregulated by more than two-fold. A total of 245 DEGs were identified between the two groups at the stationary phase, of which 123 were upregulated and 122 were downregulated. These DEGs cover crucial functional categories. Specifically, 5 genes responsible for the reverse β-oxidation pathway, 11 genes encoding ATP-binding cassette (ABC) transporters, 6 genes encoding substrate-binding protein (SBP) and 4 genes encoding phosphotransferase system (PTS) transporters were strikingly upregulated in response to the addition of lactate. These genes would be candidates for future studies aiming at understanding the regulatory mechanism of lactate conversion into CA, as well as for the improvement of CA production in strain CPB6. Conclusion: This study suggested that lactate supplementation can promote CA production by altering the expression patterns of genes involved in the essential metabolic pathways, such as central pyruvate metabolism, the reverse β-oxidation pathway, ABC and PTS transports. The findings presented herein reveal unique insights into the biomolecular effects of lactate on CA production at the gene transcriptional level.


Genome ◽  
2018 ◽  
Vol 61 (2) ◽  
pp. 121-130 ◽  
Author(s):  
Chenghao Zhang ◽  
Wenqi Dong ◽  
Zong-an Huang ◽  
MyeongCheoul Cho ◽  
Qingcang Yu ◽  
...  

Auxin plays key roles in regulating plant growth and development as well as in response to environmental stresses. The intercellular transport of auxin is mediated by the following four gene families: ATP-binding cassette family B (ABCB), auxin resistant1/like aux1 (AUX/LAX), PIN-formed (PIN), and PIN-like (PILS). Here, the latest assembled pepper (Capsicum annuum L.) genome was used to characterise and analyse the CaLAX and CaPIN gene families. Genome-wide investigations into these families, including chromosomal distributions, phytogenic relationships, and intron/exon structures, were performed. In total, 4 CaLAX and 10 CaPIN genes were mapped to 10 chromosomes. Most of these genes exhibited varied tissue-specific expression patterns assessed by quantitative real-time PCR. The expression profiles of the CaLAX and CaPIN genes under various abiotic stresses (salt, drought, and cold), exogenous phytohormones (IAA, 6-BA, ABA, SA, and MeJA), and polar auxin transport inhibitor treatments were evaluated. Most CaLAX and CaPIN genes were altered by abiotic stress at the transcriptional level in both shoots and roots, and many CaLAX and CaPIN genes were regulated by exogenous phytohormones. Our study helps to identify candidate auxin transporter genes and to further analyse their biological functions in pepper development and in its adaptation to environmental stresses.


2005 ◽  
Vol 51 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Fredrik Karlsson ◽  
Ann-Christin Malmborg-Hager ◽  
Ann-Sofie Albrekt ◽  
Carl A.K Borrebaeck

To identify Escherichia coli genes potentially regulated by filamentous phage infection, we used oligonucleotide microarrays. Genome-wide comparison of phage M13-infected and uninfected E. coli, 2 and 20 min after infection, was performed. The analysis revealed altered transcription levels of 12 E. coli genes in response to phage infection, and the observed regulation of phage genes correlated with the known in vivo pattern of M13 mRNA species. Ten of the 12 host genes affected could be grouped into 3 different categories based on cellular function, suggesting a coordinated response. The significantly upregulated genes encode proteins involved in reactions of the energy-generating phosphotransferase system and transcription processing, which could be related to phage transcription. No genes belonging to any known E. coli stress response pathways were scored as upregulated. Furthermore, phage infection led to significant downregulation of transcripts of the bacterial genes gadA, gadB, hdeA, gadE, slp, and crl. These downregulated genes are normally part of the host stress response mechanisms that protect the bacterium during conditions of acid stress and stationary phase transition. The phage-infected cells demonstrated impaired function of the oxidative and the glutamate-dependent acid resistance systems. Thus, global transcriptional analysis and functional analysis revealed previously unknown host responses to filamentous phage infection.Key words: filamentous phage infection, global transcriptional analysis, AR, Escherichia coli.


2001 ◽  
Vol 183 (24) ◽  
pp. 7329-7340 ◽  
Author(s):  
Robert Caldwell ◽  
Ron Sapolsky ◽  
Walter Weyler ◽  
Randal R. Maile ◽  
Stuart C. Causey ◽  
...  

ABSTRACT The availability of the complete sequence of the Bacillus subtilis chromosome (F. Kunst et al., Nature 390:249–256, 1997) makes possible the construction of genome-wide DNA arrays and the study of this organism on a global scale. Because we have a long-standing interest in the effects of scoC on late-stage developmental phenomena as they relate toaprE expression, we studied the genome-wide effects of ascoC null mutant with the goal of furthering the understanding of the role of scoC in growth and developmental processes. In the present work we compared the expression patterns of isogenic B. subtilis strains, one of which carries a null mutation in the scoC locus (scoC4). The results obtained indicate thatscoC regulates, either directly or indirectly, the expression of at least 560 genes in the B. subtilisgenome. ScoC appeared to repress as well as activate gene expression. Changes in expression were observed in genes encoding transport and binding proteins, those involved in amino acid, carbohydrate, and nucleotide and/or nucleoside metabolism, and those associated with motility, sporulation, and adaptation to atypical conditions. Changes in gene expression were also observed for transcriptional regulators, along with sigma factors, regulatory phosphatases and kinases, and members of sensor regulator systems. In this report, we discuss some of the phenotypes associated with the scoCmutant in light of the transcriptome changes observed.


2019 ◽  
Author(s):  
Shuting Zhang ◽  
Chen Zhu ◽  
Yumeng Lyu ◽  
Yan Chen ◽  
Zihao Zhang ◽  
...  

Abstract Background: The APETALA2/ethylene responsive factor (AP2/ERF) superfamily members are transcription factors that regulate diverse developmental processes and stress responses in plants. They have been identified in many plants. However, little is known about the AP2/ERF superfamily in longan (Dimocarpus longan Lour.), which is an important tropical/subtropical evergreen fruit tree that produces a variety of bioactive compounds with rich nutritional and medicinal value. We conducted a genome-wide analysis of the AP2/ERF superfamily and its roles in somatic embryogenesis (SE) and developmental processes in longan. Results: A genome-wide survey of the AP2/ERF superfamily was carried out to discover its evolution and function in longan. We identified 125 longan AP2/ERF genes and classified them into the ERF (101 members), AP2 (19 members), RAV (four members) families, and one Soloist. The AP2 and Soloist genes contained one to ten introns, whereas 87 genes in the ERF and RAV families had no introns. Hormone signaling molecules such as methyl jasmonate (MeJA), abscisic acid (ABA), gibberellin, auxin, and salicylic acid (SA), and stress response cis-acting element low-temperature (55) and defense (49) boxes also were identified. We detected diverse single nucleotide polymorphisms (SNPs) between the 'Hong He Zi' (HHZ) and 'SI JI MI' (SJM) cultivars. The number of insertions and deletions (InDels) was far fewer than SNPs. The AP2 family members exhibited more alternative splicing (AS) events in different developmental processes of longan than members of the other families. Expression pattern analysis revealed that some AP2/ERF members regulated early SE and developmental processes in longan seed, root, and flower, and responded to exogenous hormones such as MeJA, SA, and ABA, and 2,4-D, a synthetic auxin. Protein interaction predictions indicated that the Baby Boom (BBM) transcription factor, which was up-regulated at the transcriptional level in early SE, may interact with the LALF/AGL15 network. Conclusions: The comprehensive analysis of molecular evolution and expression patterns suggested that the AP2/ERF superfamily may plays an important role in longan, especially in early SE, and in seed, root, flower, and young fruit. This systematic analysis provides a foundation for further functional characterization of the AP2/ERF superfamily with the aim of longan improvement.


2013 ◽  
Vol 24 (3) ◽  
pp. 246-260 ◽  
Author(s):  
Patricia L. Carlisle ◽  
David Kadosh

Candida albicans, the most common cause of human fungal infections, undergoes a reversible morphological transition from yeast to pseudohyphal and hyphal filaments, which is required for virulence. For many years, the relationship among global gene expression patterns associated with determination of specific C. albicans morphologies has remained obscure. Using a strain that can be genetically manipulated to sequentially transition from yeast to pseudohyphae to hyphae in the absence of complex environmental cues and upstream signaling pathways, we demonstrate by whole-genome transcriptional profiling that genes associated with pseudohyphae represent a subset of those associated with hyphae and are generally expressed at lower levels. Our results also strongly suggest that in addition to dosage, extended duration of filament-specific gene expression is sufficient to drive the C. albicans yeast-pseudohyphal-hyphal transition. Finally, we describe the first transcriptional profile of the C. albicans reverse hyphal-pseudohyphal-yeast transition and demonstrate that this transition involves not only down-regulation of known hyphal-specific, genes but also differential expression of additional genes that have not previously been associated with the forward transition, including many involved in protein synthesis. These findings provide new insight into genome-wide expression patterns important for determining fungal morphology and suggest that in addition to similarities, there are also fundamental differences in global gene expression as pathogenic filamentous fungi undergo forward and reverse morphological transitions.


2019 ◽  
Vol 20 (7) ◽  
pp. 1679 ◽  
Author(s):  
Ziyu Zhang ◽  
Jiamin Yan ◽  
Qing Liu ◽  
Yuhao Zhang ◽  
Jing Gong ◽  
...  

Chitin deacetylases (CDAs) are a group of enzymes involved in chitin metabolism in insects; they play a critical role in molting, pupation, and the modification of chitin. In this study, we identified several CDAs in the silkworm, Bombyx mori (BmCDA), and investigated the effect of various hormones on their expression in B. mori larvae and embryo cell lines (BmE). Eight genes encoding BmCDAs were identified in the silkworm genome. They showed different expression patterns in different tissues, and were classified into three types based on where they were expressed: the exoskeleton, digestive organs, and genital organs. Moreover, we found that some BmCDAs showed upregulated expression during the molting period, especially during the fourth molting period in larvae. We also verified that the expression of BmCDA1–6 was upregulated by treatment with 20-hydroxyecdysone not only in larvae, but also in BmE cells. Interestingly, juvenile hormone analog treatment also upregulated the expression of some BmCDAs. The overexpression of several transcription factors revealed that the POU transcription factor POUM2 may play a major role in the regulation of BmCDA expression. Finally, the silencing of BmCDA1 and BmCDA2 did not lead to abnormal phenotypes or death, but may have led to delays in silkworm pupation. These results provide important information about lepidopteran insects in terms of chitin deacetylases and the regulation of their expression.


2007 ◽  
Vol 189 (17) ◽  
pp. 6260-6265 ◽  
Author(s):  
Shaolin Chen ◽  
David B. Wilson

ABSTRACT Thermobifida fusca secretes proteins that carry out plant cell wall degradation. Using two-dimensional electrophoresis, the extracellular proteome of T. fusca grown on cellobiose was compared to that of cells grown on glucose. Extracellular proteins, the expression of which is induced by cellobiose, mainly are cellulases and cellulose-binding proteins. Other major extracellular proteins induced by cellobiose include a xylanase (Xyl10A) and two unknown proteins, the C-terminal regions of which are homologous to a lytic transglycosylase goose egg white lysozyme domain and an NLPC_P60 domain (which defines a family of cell wall peptidases), respectively. Transcriptional analysis of genes encoding cellobiose-induced proteins suggests that their expression is controlled at the transcriptional level and that their expression also is induced by cellulose. Some other major extracellular proteins produced by T. fusca grown on both cellobiose and glucose include Lam81A and three unknown proteins that are homologous to aminopeptidases and xylanases or that contain a putative NLPC_P60 domain.


Microbiology ◽  
2010 ◽  
Vol 156 (11) ◽  
pp. 3478-3491 ◽  
Author(s):  
Matthew D. Servinsky ◽  
James T. Kiel ◽  
Nicole F. Dupuy ◽  
Christian J. Sund

Transcriptional analysis was performed on Clostridium acetobutylicum with the goal of identifying sugar-specific mechanisms for the transcriptional regulation of transport and metabolism genes. DNA microarrays were used to determine transcript levels from total RNA isolated from cells grown on media containing eleven different carbohydrates, including two pentoses (xylose, arabinose), four hexoses (glucose, mannose, galactose, fructose), four disaccharides (sucrose, lactose, maltose, cellobiose) and one polysaccharide (starch). Sugar-specific induction of many transport and metabolism genes indicates that these processes are regulated at the transcriptional level and are subject to carbon catabolite repression. The results show that C. acetobutylicum utilizes symporters and ATP-binding cassette (ABC) transporters for the uptake of pentose sugars, while disaccharides and hexoses are primarily taken up by phosphotransferase system (PTS) transporters and a gluconate : H+ (GntP) transporter. The transcription of some transporter genes was induced by specific sugars, while others were induced by a subset of the sugars tested. Sugar-specific transport roles are suggested, based on expression comparisons, for various transporters of the PTS, the ABC superfamily and members of the major facilitator superfamily (MFS), including the GntP symporter family and the glycoside-pentoside-hexuronide (GPH)-cation symporter family. Additionally, updates to the C. acetobutylicum genome annotation are proposed, including the identification of genes likely to encode proteins involved in the metabolism of arabinose and xylose via the pentose phosphate pathway.


2008 ◽  
Vol 74 (24) ◽  
pp. 7709-7714 ◽  
Author(s):  
Zhen Shi ◽  
Hans P. Blaschek

ABSTRACT Clostridium beijerinckii is an anaerobic bacterium used for the fermentative production of acetone and butanol. The recent availability of genomic sequence information for C. beijerinckii NCIMB 8052 has allowed for an examination of gene expression during the shift from acidogenesis to solventogenesis over the time course of a batch fermentation using a ca. 500-gene set DNA microarray. The microarray was constructed using a collection of genes which are orthologs of members of gene families previously found to be important to the physiology of C. acetobutylicum ATCC 824. Similar to the onset of solventogenesis in C. acetobutylicum 824, the onset of solventogenesis in C. beijerinckii 8052 was concurrent with the initiation of sporulation. However, forespores and endospores developed more rapidly in C. beijerinckii 8052 than in C. acetobutylicum 824, consistent with the accelerated expression of the sigE- and sigG-regulated genes in C. beijerinckii 8052. The comparison of gene expression patterns and morphological changes in C. beijerinckii 8052 and the hyper-butanol-producing C. beijerinckii strain BA101 indicated that BA101 was less efficient in sporulation and phosphotransferase system-mediated sugar transport than 8052 but that it exhibited elevated expression of several primary metabolic genes and chemotaxis/motility genes.


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