title: Keratinase production and biodegradation of polluted secondary chicken feather wastes by a newly isolated multi heavy metal tolerant bacterium-Alcaligenes sp. AQ05-001.
abstract: Biodegradation of agricultural wastes, generated annually from poultry farms and slaughterhouses, can solve the pollution problem and at the same time yield valuable degradation products. But these wastes also constitute environmental nuisance, especially in Malaysia where their illegal disposal on heavy metal contaminated soils poses a serious biodegradation issue as feather tends to accumulate heavy metals from the surrounding environment. Further, continuous use of feather wastes as cheap biosorbent material for the removal of heavy metals from effluents has contributed to the rising amount of polluted feathers, which has necessitated the search for heavy metal-tolerant feather degrading strains. Isolation, characterization and application of a novel heavy metal-tolerant feather-degrading bacterium, identified by 16S RNA sequencing as Alcaligenes sp. AQ05-001 in degradation of heavy metal polluted recalcitrant agricultural wastes, have been reported. Physico-cultural conditions influencing its activities were studied using one-factor-at-a-time and a statistical optimisation approach. Complete degradation of 5 g/L feather was achieved with pH 8, 2% inoculum at 27 °C and incubation period of 36 h. The medium optimisation after the response surface methodology (RSM) resulted in a 10-fold increase in keratinase production (88.4 U/mL) over the initial 8.85 U/mL when supplemented with 0.5% (w/v) sucrose, 0.15% (w/v) ammonium bicarbonate, 0.3% (w/v) skim milk, and 0.01% (w/v) urea. Under optimum conditions, the bacterium was able to degrade heavy metal polluted feathers completely and produced valuable keratinase and protein-rich hydrolysates. About 83% of the feathers polluted with a mixture of highly toxic metals were degraded with high keratinase activities. The heavy metal tolerance ability of this bacterium can be harnessed not only in keratinase production but also in the bioremediation of heavy metal-polluted feather wastes.
authors: Department of Biochemistry, Faculty of Biotechnology and Bimolecular Sciences, Universiti Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia; Department of Microbiology, Faculty of Science, Bayero University, Kano, P.M.B. 3011, Kano, Nigeria.
authors: Ibrahim
authors: I
authors: Yusuf
authors: Department of Biochemistry, Faculty of Biotechnology and Bimolecular Sciences, Universiti Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia. Electronic address: aqlimaahmad@gmail.com.
authors: Siti Aqlima
authors: SA
authors: Ahmad
authors: Department of Bioprocess Technology, Faculty of Biotechnology and Bimolecular Sciences, Universiti Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia.
authors: Lai Yee
authors: LY
authors: Phang
authors: Department of Biochemistry, Faculty of Biotechnology and Bimolecular Sciences, Universiti Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia.
authors: Mohd Arif
authors: MA
authors: Syed
authors: Faculty of Medicine and Health Sciences, Universiti Sains Islam Malaysia, 13th Floor, Menara B, Persiaran MPAJ, Jalan Pandan Utama, Pandan Indah, 55100, Kuala Lumpur, Malaysia.
authors: Nor Aripin
authors: NA
authors: Shamaan
authors: Biomolecular Science Program, School of Biology, Faculty of Applied Sciences, Universiti Teknology MARA, 40450, Shah Alam, Selangor, Malaysia.
authors: Khalilah
authors: K
authors: Abdul Khalil
authors: The School of Environmental Engineering, Universiti Malaysia Perlis, Kompleks Pengajian Kejuruteraan Jejawi 3, 02600, Arau, Perlis, Malaysia.
authors: Farrah Aini
authors: FA
authors: Dahalan
authors: Department of Biochemistry, Faculty of Biotechnology and Bimolecular Sciences, Universiti Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia.
authors: Mohd Yunus
authors: MY
authors: Shukor
mesh_terms: D000383:Agriculture; D000421:Alcaligenes / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D002645:Chickens; D024901:Drug Resistance, Multiple, Bacterial; D004785:Environmental Pollutants / Q000633:toxicity; D005241:Feathers / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology / Q000379:methods*; D008296:Malaysia; D019216:Metals, Heavy / Q000633:toxicity*; D010447:Peptide Hydrolases / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S; D013696:Temperature; D014866:Waste Products
chemical_list: D004785:Environmental Pollutants; D019216:Metals, Heavy; D012336:RNA, Ribosomal, 16S; D014866:Waste Products; D010447:Peptide Hydrolases; C035855:keratinase
keywords: Alcaligenes sp. AQ05-001; Biodegradation; Feather degradation; Heavy metals; Keratinase; Response surface methodology (RSM)