Functional Analysis of Methylomonas sp. DH-1 Genome as a Promising Biocatalyst for Bioconversion of Methane to Valuable Chemicals

Abstract

Methylomonas sp. DH-1, newly isolated from the activated sludge of a brewery plant, has been used as a promising biocatalytic platform for the conversion of methane to value-added chemicals. Methylomonas sp. DH-1 can efficiently convert methane and propane into methanol and acetone with a specific productivity of 4.31 and 0.14 mmol/g cell/h, the highest values ever reported, respectively. Here, we present the complete genome sequence of Methylomonas sp. DH-1 which consists of a 4.86 Mb chromosome and a 278 kb plasmid. The existence of a set of genes related to one-carbon metabolism and various secondary metabolite biosynthetic pathways including carotenoid pathways were identified. Interestingly, Methylomonas sp. DH-1 possesses not only the genes of the ribulose monophosphate cycle for type I methanotrophs but also the genes of the serine cycle for type II. Methylomonas sp. DH-1 accumulated 80 mM succinate from methane under aerobic conditions, because DH-1 has 2-oxoglutarate dehydrogenase activity and the ability to operate the full TCA cycle. Availability of the complete genome sequence of Methylomonas sp. DH-1 enables further investigations on the metabolic engineering of this strain for the production of value-added chemicals from methane.

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

“…C30 carotenoid biosynthesis related genes crtN, ald, and crtNb are contained in Methylomonas sp. [24]. It was confirmed that C30 carotenoid was synthesized via mutagenesis analysis.…”

“…Methanotrophs currently play an important role in a wide range of biotechnological applications with their ability to utilize single carbon (C1) feedstock, i.e., methane and methanol, to produce various high-value compounds. Our genome analysis indicated the existence of a set of genes encoding the methylerythritol 4-phosphate (MEP) pathway in both type I and type II methanotrophs [24] ( Table 1). Interestingly, many strains belong to type I methanotrophs such as Methylomonas sp.…”

“…Typically, type I methanotrophs assimilate formaldehyde through the RuMP pathway (including Type X Methylocaldum and Methylococcus). They also form a flat, disc-shaped inner cytoplasm and have a TCA cycle lacking α-ketoglurarate dehydrogenase activity [24]. However, there have been many novel findings related to the methane metabolism of this group that have been reported recently.…”

Biocatalysis and Biotransformations

“…Finally, in the present issue, Coscolín and coworkers [36] and Nguyen and coworkers [37] investigated the properties and catalytic performance of biocatalysts newly isolated from genomes and metagenomes. In particular, Coscolín and coworkers investigated an ample set of metagenomicsderived esterases and lipases to reveal the extent by which promiscuity and selectivity co-exist in these catalytically-important biocatalysts, so as to identify chiral selective and promiscuous esterases and lipases.…”

Identification of a cytosine methyltransferase that improves transformation efficiency in Methylomonas sp. DH-1

“…DH-1 was isolated from brewery waste sludge, and several engineering tools have been developed [18]. This bacterium has been favored in diverse examples of metabolic engineering: the conversion of methane to methanol [18] and the production of value-added chemicals such as acetone [19,20], succinate [21], and D-lactate [22].…”