TY - JOUR
T1 - Metabolic and stress responses of Acinetobacter oleivorans DR1 during long-chain alkane degradation
AU - Park, Chulwoo
AU - Shin, Bora
AU - Jung, Jaejoon
AU - Lee, Yunho
AU - Park, Woojun
N1 - Funding Information:
Received 27 October, 2016; revised 9 August, 2017; accepted 10 August, 2017. *For correspondence. E-mail wpark@korea.ac.kr; Tel. +82-2-3290-3067; Fax +82-2-953-0737. Microbial Biotechnology (2017) 10(6), 1809–1823 doi:10.1111/1751-7915.12852 Funding information This work was supported by the National Research Foundation of Korea (NRF) grant-funded by the Korea government (MSIP) (No. NRF-2017R1A2B4005838) WP was supported by a Korea University Grant.
Publisher Copyright:
© 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.
PY - 2017/11
Y1 - 2017/11
N2 - Acinetobacter oleivorans DR1 can utilize C12–C30 alkanes as a sole carbon source but not short-chain alkanes (C6, C10). Two copies of each alkB-, almA- and ladA-type alkane hydroxylase (AH) are present in the genome of DR1 cells. Expression and mutational analyses of AHs showed that alkB1 and alkB2 are the major AH-encoding genes under C12–C30, and the roles of other almA- and ladA genes are negligible. Our data suggested that AlkB1 is responsible for long-chain alkane utilization (C24–C26), and AlkB2 is important for medium-chain alkane (C12–C16) metabolism. Phylogenetic analyses revealed large incongruities between phylogenies of 16S rRNA and each AH gene, which implies that A. oleivorans DR1 has acquired multiple alkane hydroxylases through horizontal gene transfer. Transcriptomic and qRT-PCR analyses suggested that genes participating in the synthesis of siderophore, trehalose and poly 3-hydroxybutyrate (PHB) were expressed at much higher levels when cells used C30 than when used succinate as a carbon source. The following biochemical assays supported our gene expression analyses: (i) quantification of siderophore, (ii) measurement of trehalose and (iii) observation of PHB storage. Interestingly, highly induced both ackA gene encoding an acetate kinase A and pta gene encoding a phosphotransacetylase suggested unusual ATP synthesis during C30 alkane degradation, which was demonstrated by ATP measurement using the ΔackA mutant. Impaired growth of the ΔaceA mutant indicated that the glyoxylate shunt pathway is important when C30 alkane is utilized. Our data provide insight into long-chain alkane degradation in soil microorganisms.
AB - Acinetobacter oleivorans DR1 can utilize C12–C30 alkanes as a sole carbon source but not short-chain alkanes (C6, C10). Two copies of each alkB-, almA- and ladA-type alkane hydroxylase (AH) are present in the genome of DR1 cells. Expression and mutational analyses of AHs showed that alkB1 and alkB2 are the major AH-encoding genes under C12–C30, and the roles of other almA- and ladA genes are negligible. Our data suggested that AlkB1 is responsible for long-chain alkane utilization (C24–C26), and AlkB2 is important for medium-chain alkane (C12–C16) metabolism. Phylogenetic analyses revealed large incongruities between phylogenies of 16S rRNA and each AH gene, which implies that A. oleivorans DR1 has acquired multiple alkane hydroxylases through horizontal gene transfer. Transcriptomic and qRT-PCR analyses suggested that genes participating in the synthesis of siderophore, trehalose and poly 3-hydroxybutyrate (PHB) were expressed at much higher levels when cells used C30 than when used succinate as a carbon source. The following biochemical assays supported our gene expression analyses: (i) quantification of siderophore, (ii) measurement of trehalose and (iii) observation of PHB storage. Interestingly, highly induced both ackA gene encoding an acetate kinase A and pta gene encoding a phosphotransacetylase suggested unusual ATP synthesis during C30 alkane degradation, which was demonstrated by ATP measurement using the ΔackA mutant. Impaired growth of the ΔaceA mutant indicated that the glyoxylate shunt pathway is important when C30 alkane is utilized. Our data provide insight into long-chain alkane degradation in soil microorganisms.
UR - http://www.scopus.com/inward/record.url?scp=85028665710&partnerID=8YFLogxK
U2 - 10.1111/1751-7915.12852
DO - 10.1111/1751-7915.12852
M3 - Article
C2 - 28857443
AN - SCOPUS:85028665710
SN - 1751-7907
VL - 10
SP - 1809
EP - 1823
JO - Microbial Biotechnology
JF - Microbial Biotechnology
IS - 6
ER -