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On-line Access: 2025-11-19
Received: 2024-10-14
Revision Accepted: 2024-12-30
Crosschecked: 2025-11-19
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Citations: Bibtex RefMan EndNote GB/T7714
Soo Yeon LEE, Kyung-Suk CHO. Acinetobacter sp. ME1: a multifunctional bacterium for phytoremediation utilizing melanin production, heavy metal tolerance, and plant growth promotion[J]. Journal of Zhejiang University Science B, 2025, 26(11): 1103-1120.
@article{title="Acinetobacter sp. ME1: a multifunctional bacterium for phytoremediation utilizing melanin production, heavy metal tolerance, and plant growth promotion",
author="Soo Yeon LEE, Kyung-Suk CHO",
journal="Journal of Zhejiang University Science B",
volume="26",
number="11",
pages="1103-1120",
year="2025",
publisher="Zhejiang University Press & Springer",
doi="10.1631/jzus.B2400522"
}
%0 Journal Article
%T Acinetobacter sp. ME1: a multifunctional bacterium for phytoremediation utilizing melanin production, heavy metal tolerance, and plant growth promotion
%A Soo Yeon LEE
%A Kyung-Suk CHO
%J Journal of Zhejiang University SCIENCE B
%V 26
%N 11
%P 1103-1120
%@ 1673-1581
%D 2025
%I Zhejiang University Press & Springer
%DOI 10.1631/jzus.B2400522
TY - JOUR
T1 - Acinetobacter sp. ME1: a multifunctional bacterium for phytoremediation utilizing melanin production, heavy metal tolerance, and plant growth promotion
A1 - Soo Yeon LEE
A1 - Kyung-Suk CHO
J0 - Journal of Zhejiang University Science B
VL - 26
IS - 11
SP - 1103
EP - 1120
%@ 1673-1581
Y1 - 2025
PB - Zhejiang University Press & Springer
ER -
DOI - 10.1631/jzus.B2400522
Abstract: Microorganisms inhabiting soils contaminated with heavy metals produce melanin, a dark brown pigment, as a survival strategy. In this study, a melanin-producing bacterium, Acinetobacter sp. ME1, with heavy metal tolerance and plant growth-promoting traits, was isolated from abandoned mine soil. Strain ME1 exhibited growth at concentrations of Zn up to 250 mg/L, Cd and Pb up to 100 mg/L, and Cr up to 50 mg/L. It had the ability to produce the plant hormone indole-3-acetic acid and siderophores along with 1-aminocyclopropane-1-carboxylic acid deaminase and protease activities. Additionally, it showed antioxidant activity, including catalase and 2,2-diphenyl-1-picryhydrazyl (DPPH) scavenging activities. The optimal conditions for melanin production by ME1 were a pH of 7 and a temperature of 35 °C. At 1000 mg/L, ME1-extracted melanin exhibited DPPH radical scavenging activity of (25.040±0.007)%, a sun protection factor of 15.200±0.260, and 19.6% antibacterial activity against the plant pathogen Xanthomonas campestris. Furthermore, its adsorption capacity was (0.235±0.073) mg/g melanin for Zn and (0.277±0.008) mg/g melanin for Ni. In plants of Brassica chinensis grown under conditions of hydroponic cultivation with single heavy metal contamination of Cd, Zn, Pb, or Cr, the removal efficiency of each heavy metal was improved by 0.1‒1.8 times after 3 d following inoculation with the strain ME1 compared to the plants grown under the same conditions without inoculation. In addition, ME1 inoculation improved the removal efficiency of each heavy metal by 0.1‒1.0 times under multiple heavy metal contamination conditions. These findings suggest that Acinetobacter sp. ME1 could be used to enhance phytoremediation efficiency in heavy metal-contaminated soils. Moreover, the melanin it produces also holds promise in cosmetics, household products, and medical applications due to its photoprotective, antioxidant, and antimicrobial properties.
[1]AbbasS, JavedMT, ShahidM, et al., 2020. Acinetobacter sp. SG-5 inoculation alleviates cadmium toxicity in differentially Cd tolerant maize cultivars as deciphered by improved physio-biochemical attributes, antioxidants and nutrient physiology. Plant Physiol Bioch, 155:815-827.
[2]AbdelaalK, AlkahtaniM, AttiaK, et al., 2021. The role of plant growth-promoting bacteria in alleviating the adverse effects of drought on plants. Biology, 10(6):520.
[3]AkramW, KhanWU, ShahAA, et al., 2021. Liquiritoside alleviated Pb induced stress in Brassica rapa subsp. Parachinensis: modulations in glucosinolate content and some physiochemical attributes. Front Plant Sci, 12:722498.
[4]AliSS, MorsyR, El-ZawawyNA, et al., 2017. Synthesized zinc peroxide nanoparticles (ZnO2-NPs): a novel antimicrobial, anti-elastase, anti-keratinase, and anti-inflammatory approach toward polymicrobial burn wounds. Int J Nanomed, 12:6059-6073.
[5]AntonyTMP, KrishnaAR, JayalekshmiSK, et al., 2023. Isolation and elucidation of Bacterial Melanin’s Sun Protection Factor (SPF) for photoprotection in cosmetics. J Pure Appl Microbiol, 17(1):449-455.
[6]ArunG, EyiniM, GunasekaranP, 2015. Characterization and biological activities of extracellular melanin produced by Schizophyllum commune (Fries). Indian J Exp Biol, 53(6):380-387.
[7]BanerjeeA, RoychoudhuryA, 2023. Bio-priming with a novel plant growth-promoting Acinetobacter indicus strain alleviates arsenic-fluoride co-toxicity in rice by modulating the physiome and micronutrient homeostasis. Appl Biochem Biotechnol, 195(11):6441-6464.
[8]BayramS, 2021. Production, purification, and characterization of Streptomyces sp. strain MPPS2 extracellular pyomelanin pigment. Arch Microbiol, 203(7):4419-4426.
[9]BazziW, Abou FayadAG, NasserA, et al., 2020. Heavy metal toxicity in armed conflicts potentiates AMR in A. baumannii by selecting for antibiotic and heavy metal co-resistance mechanisms. Front Microbiol, 11:68.
[10]CanalSB, BozkurtMA, YílmazH, 2023. Humic acid ameliorates phytoremediation, plant growth and antioxidative enzymes in forage turnip (Brassica rapa L.). Plant Soil Environ, 69(12):567-576.
[11]CastaldiS, PetrilloC, DonadioG, et al., 2021. Plant growth promotion function of Bacillus sp. strains isolated from salt-pan rhizosphere and their biocontrol potential against Macrophomina phaseolina. Int J Mol Sci, 22(7):3324.
[12]ChoiKY, 2021. Bioprocess of microbial melanin production and isolation. Front Bioeng Biotechnol, 9:765110.
[13]Coelho-SouzaT, MartinsN, MaiaF, et al., 2014. Pyomelanin production: a rare phenotype in Acinetobacter baumannii. J Med Microbiol, 63(1):152-154.
[14]CorreaN, CovarrubiasC, RodasPI, et al., 2017. Differential antifungal activity of human and cryptococcal melanins with structural discrepancies. Front Microbiol, 8:1292.
[15]DadachovaE, BryanRA, HowellRC, et al., 2008. The radioprotective properties of fungal melanin are a function of its chemical composition, stable radical presence and spatial arrangement. Pigment Cell Melanoma Res, 21(2):192-199.
[16]DarwishER, KalilH, AlqahtaniW, et al., 2021. Fast and reliable synthesis of melanin nanoparticles with fine-tuned metal adsorption capacities for studying heavy metal ions uptake. Nanotechnol Sci Appl, 14:101-111.
[17]DeepthiSS, Mohan ReddyK, MishraN, et al., 2021. Melanin production by Pseudomonas sp. and in silico comparative analysis of tyrosinase gene sequences. BioTechnologia, 102(4):411-424.
[18]DutraEA, DAGDCEOliveira, Kedor-HackmannERM, et al., 2004. Determination of sun protection factor (SPF) of sunscreens by ultraviolet spectrophotometry. Rev Bras Ciênc Farm, 40(3):381-385.
[19]El-AlksharEA, Abou-AlyHE, TewfikeTA, et al., 2018. Isolation and characterization of zinc tolerant bacteria from contaminated sediments and soils in Egypt. 4th International Conference on Biotechnology Applications in Agriculture (ICBAA),Benha University, Moshtohor and Hurghada, Egypt, p.265-274.
[20]El-NaggarNEA, El-EwasySM, 2017. Bioproduction, characterization, anticancer and antioxidant activities of extracellular melanin pigment produced by newly isolated microbial cell factories Streptomyces glaucescens NEAE-H. Sci Rep, 7:42129.
[21]El-ZawawyNA, KenawyER, AhmedS, et al., 2024. Bioproduction and optimization of newly characterized melanin pigment from Streptomyces djakartensis NSS-3 with its anticancer, antimicrobial, and radioprotective properties. Microb Cell Fact, 23:23.
[22]EskandariS, EtemadifarZ, 2020. Isolation and characterization of melanin producing Pseudomonas stutzeri strain UIS2 in the presence of l-tyrosine and survey of biological properties of its melanin. Iran J Med Microbiol, 14(1):70-83.
[23]EskandariS, EtemadifarZ, 2021. Biocompatibility and radioprotection by newly characterized melanin pigment and its production from Dietzia schimae NM3 in optimized whey medium by response surface methodology. Ann Microbiol, 71:17.
[24]FitriyantiD, MubarikNR, TjahjoleksonoA, 2017. Characterization and identification of phosphate solubilizing bacteria isolate GPC3.7 from limestone mining region. IOP Conf Ser Earth and Environ Sci, 58:012016.
[25]GhadgeV, KumarP, SinghS, et al., 2020. Natural melanin produced by the endophytic Bacillus subtilis 4NP-BL associated with the halophyte Salicornia brachiata. J Agric Food Chem, 68(25):6854-6863.
[26]GordhanbhaiPM, JignaC, KurianNK, 2022. Halophilic bacteria Bacillus altitudinis MIM2 producing bioactive melanin isolated from Mundra port, Kutch, Gujarat, India. bioRxiv, in press.
[27]HaqueMM, MosharafMK, HaqueMA, et al., 2021. Biofilm formation, production of matrix compounds and biosorption of copper, nickel and lead by different bacterial strains. Front Microbiol, 12:615113.
[28]HayatR, DinG, FarooqiA, et al., 2023. Characterization of melanin pigment from Aspergillus terreus LCM8 and its role in cadmium remediation. Int J Environ Sci Technol, 20(3):3151-3160.
[29]Herrera-QuiterioA, Toledo-HernándezE, Aguirre-NoyolaJL, et al., 2020. Antagonic and plant growth-promoting effects of bacteria isolated from mine tailings at El Fraile, Mexico. Rev Arge Microbiol, 52(3):231-239.
[30]HuWL, DaiDH, HuangGR, et al., 2015. Isolation and characterization of extracellular melanin produced by Chroogomphus rutilus D447. Am J Food Technol, 10(2):68-77.
[31]IqbalZ, LaiEPC, AvisTJ, 2012. Antimicrobial effect of polydopamine coating on Escherichia coli. J Mater Chem, 22(40):21608-21612.
[32]JiangJ, PanCH, XiaoAP, et al., 2017. Isolation, identification, and environmental adaptability of heavy-metal-resistant bacteria from ramie rhizosphere soil around mine refinery. 3 Biotech, 7:5.
[33]KangSM, HoqueMIU, WooJI, et al., 2023. Mitigation of salinity stress on soybean seedlings using indole acetic acid-producing Acinetobacter pittii YNA40. Agriculture, 13(5):1021.
[34]KarampatakisT, TsergouliK, BehzadiP, 2024. Pan-genome plasticity and virulence factors: a natural treasure trove for Acinetobacter baumannii. Antibiotics, 13(3):257.
[35]KimDJ, JuKY, LeeJK, 2012. The synthetic melanin nanoparticles having an excellent binding capacity of heavy metal ions. Bull Korean Chem Soc, 33(11):3788-3792.
[36]KimJY, KimHS, LeeSM, et al., 2020. Plant growth promoting and disease controlling activities of Pseudomonas geniculata ANG3, Exiguobacterium acetylicum ANG40 and Burkholderia stabilis ANG51 isolated from soil. Microbiol Biotechnol Lett, 48(1):38-47.
[37]KourD, KaurT, DeviR, et al., 2023. Co-inoculation of nitrogen fixing and potassium solubilizing Acinetobacter sp. for growth promotion of onion (Allium cepa). Biologia, 78(9):2635-2641.
[38]KuttanSP, AbdulazizA, ChekidhenkuzhiyilJ, et al., 2023. Characterization of pyomelanin secreted by Shewanella sp. and their application in metal recovery. Environ Sci Pollut Res, 30(3):6705-6715.
[39]LeeSM, KimJY, KimHS, et al., 2021. Characterization of potential plant growth-promoting rhizobacteria as biological agents with antifungal activity, plant growth-promoting activity, and mineral solubilizing activity. J Life Sci, 31(7): 641-653.
[40]LeeSY, LeeYY, ChoKS, 2021. Characterization of heavy metal tolerant and plant growth-promoting rhizobacteria isolated from soil contaminated with heavy metal and diesel. Microbiol Biotechnol Lett, 49(3):413-424.
[41]LiuYL, AiKL, LuLH, 2014. Polydopamine and its derivative materials: synthesis and promising applications in energy, environmental, and biomedical fields. Chem Rev, 114(9):5057-5115.
[42]LoiJ, YiTS, PinsaA, et al., 2020. Pyomelanin production from a marine isolate of Acinetobacter Spp. Int J Curr Microbiol Appl Sci, 9(6):2250-2259.
[43]MaherS, MahmoudM, RizkM, et al., 2020. Synthetic melanin nanoparticles as peroxynitrite scavengers, photothermal anticancer and heavy metals removal platforms. Environ Sci Pollut Res, 27(16):19115-19126.
[44]ManirethanV, RavalK, RajanR, et al., 2018. Kinetic and thermodynamic studies on the adsorption of heavy metals from aqueous solution by melanin nanopigment obtained from marine source: Pseudomonas stutzeri. J Environ Manage, 214:315-324.
[45]ManivasaganP, VenkatesanJ, SenthilkumarK, et al., 2013. Isolation and characterization of biologically active melanin from Actinoalloteichus sp. MA-32. Int J Biol Macromol, 58:263-274.
[46]MathewD, BhatSG, 2022. Pseudomonas stutzeri as biofactories for melanin nanoparticle synthesis and its anti-oxidative and antibiofilm potential evaluation. BioNanoScience, 12(3):912-926.
[47]MichaelHSR, SubiramanianSR, ThyagarajanD, et al., 2023. Melanin biopolymers from microbial world with future perspectives—a review. Arch Microbiol, 205(9):306.
[48]Montes-RobledoA, Baena-BaldirisD, Baldiris-AvilaR, 2024. Reduction of Cr(VI) by planktonic cells and biofilm of Acinetobacter sp. (ADHR1) isolated from electroplating wastewater. Environ Technol Innov, 33:103521.
[49]MouWS, KaoYT, MichardE, et al., 2020. Ethylene-independent signaling by the ethylene precursor ACC in Arabidopsis ovular pollen tube attraction. Nat Commun, 11:4082.
[50]Muñoz-TorresP, Cárdenas-NinasivinchaS, AguilarY, 2024. Exploring the agricultural applications of microbial melanin. Microorganisms, 12(7):1352.
[51]NadheSB, WadhwaniSA, SinghR, et al., 2020. Green synthesis of AuNPs by Acinetobacter sp. GWRVA25: optimization, characterization, and its antioxidant activity. Front Chem, 8:474.
[52]OhKY, KimJY, LeeSM, et al., 2021. Plant growth-promoting activity characteristics of Bacillus strains in the rhizosphere. Microbiol Biotechnol Lett, 49(3):403-412.
[53]PandeyS, MeshramV, YehiaHM, et al., 2024. Efficient production and characterization of melanin from Thermothelomyces hinnuleus SP1, isolated from the Coal Mines of Chhattisgarh, India. Front Microbiol, 14:1320116.
[54]PengZ, LuoS, ZhaoDD, et al., 2023. Biosynthetic melanin with excellent performance can be used for heavy metal adsorption. J Clean Prod, 385:135655.
[55]PetrováN, KiskováJ, KolesárováM, et al., 2023. Genetic basis of Acinetobacter sp. K1 adaptation mechanisms to extreme environmental conditions. Life, 13(8):1728.
[56]QadirM, HussainA, ShahM, et al., 2023. Pantoea conspicua promoted sunflower growth and engulfed rhizospheric arsenate by secreting exopolysaccharide. Plant Physiol Bioch, 201:107826.
[57]RaniN, RaniS, PatelH, et al., 2023. Characterization and investigation of antioxidant and antimicrobial activity of zinc oxide nanoparticles prepared using leaves extract of Nyctanthes arbor-tristis. Inorg Chem Commun, 150:110516.
[58]RaoKVR, RaoTR, 2013. Molecular characterization and its antioxidant activity of a newly isolated Streptomyces coelicoflavus BC 01 from mangrove soil. J Young Pharm, 5(4):121-126.
[59]ReddyN, DeekondaV, SeshagiriS, et al., 2022. Production, characterization and applications of proteases produced by Bacillus licheniformis, Acinetobacter pittii and Aspergillus niger using neem seed oil cake as the substrate. Ind Crop Prod, 187:115403.
[60]RizviA, AhmedB, ZaidiA, et al., 2019. Bioreduction of toxicity influenced by bioactive molecules secreted under metal stress by Azotobacter chroococcum. Ecotoxicology, 28(3):302-322.
[61]RudrappaM, KumarRS, BasavarajappaDS, et al., 2023. Penicillium citrinum NP4 mediated production, extraction, physicochemical characterization of the melanin, and its anticancer, apoptotic, photoprotection properties. Int J Biol Macromol, 245:125547.
[62]SchneiderSL, LimHW, 2019. A review of inorganic UV filters zinc oxide and titanium dioxide. Photodermatol Photoimmunol Photomed, 35(6):442-446.
[63]ShanujaSK, IswaryaS, SrideviJ, et al., 2018. Exploring the UVB-protective efficacy of melanin precursor extracted from marine imperfect fungus: featuring characterization and application studies under in vitro conditions. Int Microbiol, 21(1-2):59-71.
[64]SharmaP, BanoA, NaddaAK, et al., 2022. Crosstalk and gene expression in microorganisms under metals stress. Arch Microbiol, 204(7):410.
[65]SolanoF, 2020. Photoprotection and skin pigmentation: melanin-related molecules and some other new agents obtained from natural sources. Molecules, 25(7):1537.
[66]SunLN, ZhangXH, OuyangWK, et al., 2022. Lowered Cd toxicity, uptake and expression of metal transporter genes in maize plant by ACC deaminase-producing bacteria Achromobacter sp. J Hazard Mater, 423:127036.
[67]SurendirakumarK, PandeyRR, MuthukumarT, et al., 2022. Characterization and biological activities of melanin pigment from root endophytic fungus, Phoma sp. RDSE17. Arch Microbiol, 204(3):171.
[68]TaranginiK, MishraS, 2014. Production of melanin by soil microbial isolate on fruit waste extract: two step optimization of key parameters. Biotechnol Rep, 4:139-146.
[69]TongCQ, LuoJ, XieCL, et al., 2023. Characterization and biological activities of melanin from the medicinal fungi Ophiocordyceps sinensis. Int J Mol Sci, 24(12):10282.
[70]Tran-LyAN, RiberaJ, SchwarzeFWMR, et al., 2020. Fungal melanin-based electrospun membranes for heavy metal detoxification of water. Sustain Mater Technol, 23:e00146.
[71]TyrrellR, 1998. Antioxidants in protection from UV-induced damage. Pathophysiology, 1001(5):268.
[72]van VeenhuyzenB, ChirwaEMN, BrinkHG, 2021. Microbial Pb(II) precipitation: the role of biosorption as a Pb(II) removal mechanism. Chem Eng Trans, 86:181-186.
[73]WangPP, WeiHY, KeT, et al., 2023. Characterization and genome analysis of Acinetobacter oleivorans S4 as an efficient hydrocarbon-degrading and plant-growth-promoting rhizobacterium. Chemosphere, 331:138732.
[74]WangXY, CaiDB, JiMF, et al., 2022. Isolation of heavy metal-immobilizing and plant growth-promoting bacteria and their potential in reducing Cd and Pb uptake in water spinach. Sci Total Environ, 819:153242.
[75]YasinNA, KhanWU, AhmadSR, et al., 2019. Role of Acinetobacter sp. CS9 in improving growth and phytoremediation potential of Catharanthus longifolius under cadmium stress. Pol J Environ Stud, 28(1):435-443.
[76]ZerradA, AnissiJ, GhanamJ, et al., 2014. Antioxidant and antimicrobial activities of melanin produced by a Pseudomonas balearica strain. J Biotechnol Lett, 5(1):87-94.
[77]ZhangXY, KongDW, LiuXY, et al., 2021. Combined microbial degradation of crude oil under alkaline conditions by Acinetobacter baumannii and Talaromyces sp. Chemosphere, 273:129666.
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