Exploration of bioflocculant production of endophytic bacterium: assessment of characteristics and efficiency of its bioflocculant in wastewater treatment

Abstract

Endophytic bacteria are promising sources of potent bioflocculants, yet their diversity, biosynthetic potential and utility remain underexplored. This study focused on isolating bioflocculant-producing endophytes from Adansonia digitata, exploration of biosynthetic gene clusters and application of its bioflocculant in wastewater treatment. The standard method and 16S rRNA analysis were used for isolation and identification of endophytic bacteria. The polymerase chain reaction was employed to detect the presence of Type I Polyketide Synthase (PKS-I KS), Type II polyketide synthase and non-ribosomal peptide synthetase gene clusters. The infrared spectrometry, energy-dispersive X-ray and X-ray diffraction analysis were employed for identification of functional units, elements and crystallinity. Its efficiency was evaluated in wastewater treatment using the Jar test. Amongst the 18 isolates, Isolate Gt18, which was identified as Bacillus albus, had the highest bioflocculant production with flocculating activity of 99%. It revealed the presence of PKS-II. Its bioflocculant composed of hydroxyl, amine and carbonyl functional groups. It had carbon (1.48%), oxygen (40.47%), phosphate (17.44%) and potassium (28.58%). It revealed crystalline nature. It reduced chemical oxygen demand and turbidity by 70 and 99.8% for sewage wastewater and 57 and 75% for brewery wastewater, respectively. The bioflocculant from B. albus illustrated high potential applicability in wastewater treatment.