Synthesizing value-added products from methane by a new <i>Methylomonas</i>

Guo, Wei; Li, Demao; He, Rong; Wu, Minghuo; Chen, Wuxi; Gao, Feng; Zhang, Zhidan; Yao, Yonghong; Yu, Liang; Chen, Shulin

doi:10.1111/jam.13581

Cited by 18 publications

(14 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As described above, methanol changed transcriptional levels for the carotenoid and hopanoid biosynthesis pathways, which both provide antioxidants [44]. In addition, a pigmented carotenoid in Methylomonas exhibited high antioxidative activities [45]. Based on the changes in the carotenoid and hopanoid profiles, we hypothesized that methanol might induce oxidative stress in Methylomonas sp.…”

Section: Resultsmentioning

confidence: 99%

A comparative transcriptome analysis of the novel obligate methanotroph Methylomonas sp. DH-1 reveals key differences in transcriptional responses in C1 and secondary metabolite pathways during growth on methane and methanol

2019

View full text Add to dashboard Cite

BackgroundMethanotrophs play an important role in biotechnological applications, with their ability to utilize single carbon (C1) feedstock such as methane and methanol to produce a range of high-value compounds. A newly isolated obligate methanotroph strain, Methylomonas sp. DH-1, became a platform strain for biotechnological applications because it has proven capable of producing chemicals, fuels, and secondary metabolites from methane and methanol. In this study, transcriptome analysis with RNA-seq was used to investigate the transcriptional change of Methylomonas sp. DH-1 on methane and methanol. This was done to improve knowledge about C1 assimilation and secondary metabolite pathways in this promising, but under-characterized, methane-bioconversion strain.ResultsWe integrated genomic and transcriptomic analysis of the newly isolated Methylomonas sp. DH-1 grown on methane and methanol. Detailed transcriptomic analysis indicated that (i) Methylomonas sp. DH-1 possesses the ribulose monophosphate (RuMP) cycle and the Embden–Meyerhof–Parnas (EMP) pathway, which can serve as main pathways for C1 assimilation, (ii) the existence and the expression of a complete serine cycle and a complete tricarboxylic acid (TCA) cycle might contribute to methane conversion and energy production, and (iii) the highly active endogenous plasmid pDH1 may code for essential metabolic processes. Comparative transcriptomic analysis on methane and methanol as a sole carbon source revealed different transcriptional responses of Methylomonas sp. DH-1, especially in C1 assimilation, secondary metabolite pathways, and oxidative stress. Especially, these results suggest a shift of central metabolism when substrate changed from methane to methanol in which formaldehyde oxidation pathway and serine cycle carried more flux to produce acetyl-coA and NADH. Meanwhile, downregulation of TCA cycle when grown on methanol may suggest a shift of its main function is to provide de novo biosynthesis, but not produce NADH.ConclusionsThis study provides insights into the transcriptomic profile of Methylomonas sp. DH-1 grown on major carbon sources for C1 assimilation, providing in-depth knowledge on the metabolic pathways of this strain. These observations and analyses can contribute to future metabolic engineering with the newly isolated, yet under-characterized, Methylomonas sp. DH-1 to enhance its biochemical application in relevant industries.Electronic supplementary materialThe online version of this article (10.1186/s12864-019-5487-6) contains supplementary material, which is available to authorized users.

show abstract

Section: Resultsmentioning

confidence: 99%

A comparative transcriptome analysis of the novel obligate methanotroph Methylomonas sp. DH-1 reveals key differences in transcriptional responses in C1 and secondary metabolite pathways during growth on methane and methanol

2019

View full text Add to dashboard Cite

show abstract

“…Additionally, lycopene was naturally produced in Methylomonas sp. ZR1, as confirmed by HPLC-DAD and HPLC-MS/MS analysis methods [54].…”

Section: C30 and C40: Carotenoidsmentioning

confidence: 62%

Bioproduction of Isoprenoids and Other Secondary Metabolites Using Methanotrophic Bacteria as an Alternative Microbial Cell Factory Option: Current Stage and Future Aspects

2019

View full text Add to dashboard Cite

Methane is a promising carbon feedstock for industrial biomanufacturing because of its low price and high abundance. Recent advances in metabolic engineering and systems biology in methanotrophs have made it possible to produce a variety of value-added compounds from methane, including secondary metabolites. Isoprenoids are one of the largest family of secondary metabolites and have many useful industrial applications. In this review, we highlight the current efforts invested to methanotrophs for the production of isoprenoids and other secondary metabolites, including riboflavin and ectoine. The future outlook for improving secondary metabolites production (especially of isoprenoids) using metabolic engineering of methanotrophs is also discussed. gas-to-liquid bioconversion using methanotrophs, such as limited mass transfer rates of methane, low volumetric productivity, and instability of recombinant strains [11].Secondary metabolites produced by plants and microorganisms have many useful biological activities. Among the many secondary metabolites, isoprenoids are the largest family of natural products, with more than 50,000 members identified [12][13][14]. Many isoprenoids have been used in many applications such as pharmaceuticals, nutraceuticals, fragrances, as well as the chemical industry. Additionally, due to the methyl-branched and cyclized hydrocarbon alkene structure, some isoprenoids have attracted more attention for their potential use as advanced biofuels. Plants are the major sources of isoprenoids. However, there are still many limitations for the production of high quantities of natural isoprenoids, including slow growth and tissue-specific biosynthesis, and difficulties in harvesting and extraction [12][13][14]. In contrast, a promising alternative method for isoprenoid production is the reconstruction of isoprenoid biosynthesis pathways from plants into microbes. The application of this approach has been extensively studied on model organisms like Escherichia coli or Saccharomyces cerevisiae for a variety of isoprenoids [12,14]. E. coli and S. cerevisiae are promising hosts since they possess simple genetic backgrounds, high growth rates as well as well-developed genetic tools. For example, high production of isoprenoid-based biofuels has been achieved in the metabolic engineering of microbes via endogenous or heterologous biosynthetic pathways in these hosts. However, the vast majority of these microbe-based isoprenoid production cases rely on sugar-based metabolism, which is likely to increase in the price of isoprenoids produced in large quantity.The use of alternative carbon sources is attractive in industrial biotechnology for isoprenoid production. Furthermore, different type of pathway regulation in different microbes utilizing unusual carbon substrate like methane can play a vital role in metabolic engineering of various microbes including model organisms. Thus, metabolic engineering of methane-utilizing methanotrophs has recently attracted much attention, due to not only cheaper price of...

show abstract

“…And for carbon skeleton compensation test, 0.1 g/l ammonium chloride with 0.3 g/l α-ketoglutaramate (α-KG), 0.4 g/l glutamate, 0.3g/l malic acid, or 0.3g/l pyruvate were simultaneously added into the NMS medium. ZR1 was cultured in flask or bubble column reactor according to the method described by Guo et al (Guo et al, 2017). When using methanol as carbon source, the initial methanol concentration was 6 g/l without specific instruction.…”

Section: Methodsmentioning

confidence: 99%

Accumulation of ammonium owing to the metabolic imbalance of carbon and nitrogen might inhibit the central metabolism in Methylomonas sp. ZR1

Zhao

et al. 2020

Preprint

View full text Add to dashboard Cite

Abstract： 12The metabolic intermediates of nitrogen source have been proved to have 13 multiple functions on the metabolism of mehthanotrophs. In this study, 14 accumulation and assimilation mechanism of the nitrate metabolic 15 intermediate ammonium in the fast growing Methylomonas sp. ZR1 was 16 analyzed. Although, nitrate salt was the best nitrogen source supporting 17 the growth of ZR1, its metabolic intermediate ammonium would 18 accumulate and inhibit ZR1. Kinetic studies indicated that accumulation 19 of NH4 + was deduced from the imbalance of nitrogen and carbon 20 metabolism. Compensation of carbon skeleton α-keto-glutaramate could 21 effectively relieve the inhibition of NH4 + to ZR1, which further approved 22 42relieve the ammonium stress according to the edible carbon source. 43Revealing the endogenous ammonium accumulation mechanism and its 44 3 metabolic adjustment effect on the central metabolism of methanotrophs, 45 was meaningful to reveal the complex coordination metabolic 46 mechanism of nitrogen and carbon in methanotrophs. 47 Introduction： 49 Methanotrophs are excellent C1 compounds assimilating microorganisms, 50 and its industrial application has a long history since 1960s. At the 51 beginning methanotrophs were used to produce single cell protein from 52 methane or methanol. Nowadays, with the development of biotechnology, 53 methanotrophs were genetic modified to produce lactic acid (Henard et 54 al., 2016; Garg et al., 2018), astaxanthin (Ye and Kelly, 2012) and 55 α-hemelune (Sonntag et al., 2015) from methane. However, the slow 56 growth nature of methanotrophs has constrained its application in 57 industrial biotechnology. 58 Efforts to optimize fermentation technologies to improve the growth rates 59 of methanotrophs on methane have been reported over the past years (Yu 60 et al., 2003; Park et al., 1991b; Shah et al., 1996; Xing et al., 2006; Han et 61 al., 2009) (Myung et al., 2016). Other factors such as the addition of 62 citrate acid (Xing et al., 2006) and adjusting the ion concentration (Leak 63 and Dalton, 1986) were also reported to have effect in improving the 64 growth rate of methanotrophs from methane. These studies indicated that 65 the growth rate of methanotrophs might be result from multi-factor 66 4 combined effects. Many studies have also proved that nitrogen sources 67 have strong effect on the growth of methanotrophs. Park et al. studied 68 several factors including the nitrogen source affected the growth of OB3b, 69 and found that nitrate depletion was responsible for the diauxic growth 70 pattern in the batch cultivation of OB3b in the bioreactor. However, its 71 growth declined much with 40 mM nitrate (Park et al., 1991). Hoefman et 72 al. found niche partitioning among methanotrophic species, with methane 73 oxidation activity responses to changes in nitrogen content being 74 dependent on the in situ methanotrophic community structure (Hoefman 75 et al., 2014). Strains have developed a complex mechanism to balance the 76 carbon and nitrogen metabolism (Commic...

show abstract

Synthesizing value-added products from methane by a new Methylomonas

Cited by 18 publications

References 44 publications

A comparative transcriptome analysis of the novel obligate methanotroph Methylomonas sp. DH-1 reveals key differences in transcriptional responses in C1 and secondary metabolite pathways during growth on methane and methanol

A comparative transcriptome analysis of the novel obligate methanotroph Methylomonas sp. DH-1 reveals key differences in transcriptional responses in C1 and secondary metabolite pathways during growth on methane and methanol

Bioproduction of Isoprenoids and Other Secondary Metabolites Using Methanotrophic Bacteria as an Alternative Microbial Cell Factory Option: Current Stage and Future Aspects

Accumulation of ammonium owing to the metabolic imbalance of carbon and nitrogen might inhibit the central metabolism in Methylomonas sp. ZR1

Contact Info

Product

Resources

About