Complete degradation of dimethyl isophthalate requires the biochemical cooperation between Klebsiella oxytoca Sc and Methylobacterium mesophilicum Sr Isolated from Wetland sediment.
Two bacterial strains Klebsiella oxytoca Sc and Methylobacterium mesophilicum Sr were isolated and identified from enrichment cultures using dimethyl isophthalate (DMI) as the sole source of carbon and energy, and mangrove sediment as an inoculum. DMI was rapidly transformed by K. oxytoca Sc in the culture with formation of monomethyl isophthalate (MMI), which accumulated in the culture medium. M. mesophilicum Sr, incapable of utilizing DMI, showed high capability of degrading MMI to a transitory intermediate isophthalic acid (IPA), which was further mineralized by this strain. The biochemical pathway of DMI degradation by these two bacteria in a consortium was proposed: DMI to MMI by K. oxytoca Sc, MMI to IPA by M. mesophilicum Sr, and IPA by both K. oxytoca Sc and M. mesophilicum Sr based on the identified degradation intermediates. The consortium comprising K. oxytoca Sc and M. mesophilicum Sr was effective in mineralization of DMI. The results suggest that complete degradation of environmental pollutant DMI requires the biochemical cooperation between different microorganisms of the mangrove environment.
Li
Jiaxi
J
Environmental and Molecular Microbiology, Key Laboratory of Tropical Marine Environment Dynamics (LED), South China Sea Institute of Oceanography, Chinese Academy of Sciences, 164 Xingang Road West, Guangzhou 510301, PR China.
Gu
Ji-Dong
JD
D001673:Biodegradation, Environmental; D019015:Geologic Sediments / Q000737:chemistry / Q000382:microbiology; D041121:Klebsiella oxytoca / Q000378:metabolism*; D020580:Methylobacterium / Q000378:metabolism*; D010795:Phthalic Acids / Q000032:analysis / Q000378:metabolism*; D014871:Water Microbiology; D053833:Wetlands
D010795:Phthalic Acids; C024629:dimethyl phthalate