title: Assessment of the factors contributing to the variations in microcystins biodegradability of the biofilms on a practical biological treatment facility.
abstract: This study revealed the biotic and abiotic parameters driving the variations in microcystins (MCs) biodegradability of a practical biological treatment facility (BTF). Results showed that similar trends of seasonal variation were seen for microcystin-LR (MCLR) biodegradability of biofilms on the BTF and indigenous MCLR-degrader population, where both peaks co-occurred in October, following the peaks of natural MCLR concentration and water temperature observed in August. The lag period might be required for accumulation of MCLR-degraders and MCLR-degrading enzyme activity. The MCLR-degrader population was correlated to temperature, MCLR and chlorophyll-a concentration in water where the biofilms submerged, indicating that these abiotic and biotic parameters exerted direct and/or indirect influences on seasonal variation in MCLR-biodegradability. In comparison, no effect of other co-existing MCs on biodegradation of one MC was observed. However, proliferation of MC-degraders along biodegradation processes positively responded to total amount of MCs, suggesting that multiple MCs contributed additively to MC-degrader proliferation.
authors.affiliation: College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Jieming
authors.initials: J
authors.lastname: Li
authors.affiliation: Faculty of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura, Ora-gun, Gunma 374-0193, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Shimizu
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Haruna
authors.initials: H
authors.lastname: Akasako
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Zhijiang
authors.initials: Z
authors.lastname: Lu
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Shohei
authors.initials: S
authors.lastname: Akiyama
authors.affiliation: Malaysia-Japan International Institute of Technology (MJIIT), Universiti Teknologi Malaysia, Jalan Semarak, Kuala Lumpur 54100, Malaysia.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Goto
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Motoo
authors.initials: M
authors.lastname: Utsumi
authors.affiliation: Malaysia-Japan International Institute of Technology (MJIIT), Universiti Teknologi Malaysia, Jalan Semarak, Kuala Lumpur 54100, Malaysia; Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan. Electronic address: Sugiura.norio.gm@u.tsukuba.ac.jp.
authors.forename: Norio
authors.initials: N
authors.lastname: Sugiura
mesh_terms: D001673:Biodegradation, Environmental; D018441:Biofilms; D004275:DNA, Ribosomal; D004798:Enzymes / Q000378:metabolism; D007564:Japan; D008387:Marine Toxins; D052998:Microcystins / Q000235:genetics / Q000378:metabolism*; D012621:Seasons; D013696:Temperature; D018508:Water Purification / Q000379:methods*
chemical_list: D004275:DNA, Ribosomal; D004798:Enzymes; D008387:Marine Toxins; D052998:Microcystins; C057862:cyanoginosin LR
keywords: Biodegradation; Biofilm; Microcystin; Seasonal variation; mlrA gene