TY - JOUR

T1 - Novel approaches and reasons to isolate methanotrophic bacteria with biotechnological potentials

T2 - recent achievements and perspectives

AU - Kwon, Miye

AU - Ho, Adrian

AU - Yoon, Sukhwan

N1 - Funding information: This research was funded by the National Research Foundation of Korea (NRF) (grant number 2015M3D3A1A01064881 and 2016K2A9A2A06004870). The authors were also financially supported by the Deutsche Forschungsgemeinschaft (grant number HO6234/1-1) and the Leibniz Universität Hannover.

PY - 2019/1

Y1 - 2019/1

N2 - The recent drop in the price of natural gas has rekindled the interests in methanotrophs, the organisms capable of utilizing methane as the sole electron donor and carbon source, as biocatalysts for various industrial applications. As heterologous expression of the methane monooxygenases in more amenable hosts has been proven to be nearly impossible, future success in methanotroph biotechnology largely depends on securing phylogenetically and phenotypically diverse methanotrophs with relatively high growth rates. For long, isolation of methanotrophs have relied on repeated single colony picking after initial batch enrichment with methane, which is a very rigorous and time-consuming process. In this review, three unconventional isolation methods devised for facilitation of the isolation process, diversification of targeted methanotrophs, and/or screening of rapid growers are summarized. The soil substrate membrane method allowed for isolation of previously elusive methanotrophs and application of high-throughput extinction plating technique facilitated the isolation procedure. Use of a chemostat with gradually increased dilution rates proved effective in screening for the fastest-growing methanotrophs from environmental samples. Development of new isolation technologies incorporating microfluidics and single-cell techniques may lead to discovery of previously unculturable methanotrophs with unexpected metabolic potentials and thus, certainly warrant future investigation.

AB - The recent drop in the price of natural gas has rekindled the interests in methanotrophs, the organisms capable of utilizing methane as the sole electron donor and carbon source, as biocatalysts for various industrial applications. As heterologous expression of the methane monooxygenases in more amenable hosts has been proven to be nearly impossible, future success in methanotroph biotechnology largely depends on securing phylogenetically and phenotypically diverse methanotrophs with relatively high growth rates. For long, isolation of methanotrophs have relied on repeated single colony picking after initial batch enrichment with methane, which is a very rigorous and time-consuming process. In this review, three unconventional isolation methods devised for facilitation of the isolation process, diversification of targeted methanotrophs, and/or screening of rapid growers are summarized. The soil substrate membrane method allowed for isolation of previously elusive methanotrophs and application of high-throughput extinction plating technique facilitated the isolation procedure. Use of a chemostat with gradually increased dilution rates proved effective in screening for the fastest-growing methanotrophs from environmental samples. Development of new isolation technologies incorporating microfluidics and single-cell techniques may lead to discovery of previously unculturable methanotrophs with unexpected metabolic potentials and thus, certainly warrant future investigation.

KW - Chemostat screening

KW - Extinction culturing

KW - Isolation techniques

KW - Methanotroph

KW - Soil substrate membrane system

UR - http://www.scopus.com/inward/record.url?scp=85055325528&partnerID=8YFLogxK

U2 - 10.1007/s00253-018-9435-1

DO - 10.1007/s00253-018-9435-1

M3 - Review article

C2 - 30315351

AN - SCOPUS:85055325528

VL - 103

JO - Applied Microbiology and Biotechnology

JF - Applied Microbiology and Biotechnology

SN - 0175-7598

IS - 1

ER -