Extraction of ligninolytic enzymes from novel Klebsiella pneumoniae strains and its application in wastewater treatment

Abstract

The presence of lignin and its derivatives in pulp effluent increases the pollution load on the environment. With an aim of better degradation and decolourization of wastewater, this study proposes the utilization of different ligninolytic enzymes from novel bacterial strains. Four novel bacterial strains of Klebsiella pneumoniae (K. pneumoniae strains NITW715076, NITW715076_1, NITW715076_2 and NITW715076_3) were isolated and identified. The ligninolytic enzymes were characterized by plate assay method. For the optimization of various process parameters of effluent sample, different approaches were used like one factor at a time and statistical optimization through response surface methodology (RSM). Further to validate the above data, enzyme activity, total phenolic concentration, GC-MS analysis and seed germination test were also performed. The ligninolytic enzymes produced were characterized as laccase and Manganese peroxidase (MnP). In lignin degradation and decolourization studies, consortia 1 (K. pneumoniae NITW715076_2 + K. pneumoniae NITW715076_1) (82.31%) was found more effective when compared to axenic culture (K. pneumoniae NITW715076_2) (74.1%). In RSM studies, Laccase and MnP activities were increased by 20% and 18%, respectively, as compared to one factor at a time optimization method. In addition, the enzyme activity for laccase and MnP after prediction by RSM was found 53338 IU/L and 147900 IU/L, respectively. The R 2 values for both the enzymes were found to be significant. Further, GC-MS analysis also showed the degradation of different organic pollutants in effluent. Lastly, the seed germination test using consortia 1 corroborated the evidence of detoxification of industrial effluent. Effluent treated by consortia 1 showed better results in degradation and decolourization of lignin and their derivatives. Therefore, consortia 1 can be used for various industrial purposes like fruit juice clarification, diagnostic purposes and enhanced bioethanol production.

Klebsiella and Enterobacter Isolated from Mangrove Wetland Soils in Thailand and Their Application in Biological Decolorization of Textile Reactive Dyes

“…K. pneumoniae strain NX-1 isolated from leaf mold samples in China could efficiently produce lignin peroxidase and laccase [ 60 ]. Four strains of K. pneumoniae isolated from the pulp and paper industry in India were designated as manganese peroxidase and laccase producing bacterium [ 61 ]. It is evidenced that Klebsiella species represent a promising source of ligninolytic enzymes.…”

Study of Production and Characterization of Laccase Enzyme from Klebsiellapneumoniae K7 Isolate

“…Laccase purified from K. pneumoniae by using ABTS as substrate. The K m values were 0.467, 3.97 and 0.38mM for NITW715076, NITW715076_1 and NITW715076_2 K. pneumoniae strains, respectively [26] .…”

Influence of lignin level of raw material on anaerobic digestion process in reorganization and performance of microbial community

“…Genera Klebsiella and Escherichia both have been known to mineralize and utilize lignin and lignin related products as carbon source. Lab-scale expression studies of laccases and manganese peroxidase (MnP) have demonstrated the lignin degradation potency of both these genera in addition to their ability for utilizing lignin degradation intermediates vanillyl alcohol and syringaldehyde (Gaur et al 2018;Tian et al 2014). Zeng et al (2011) studied the extraction and over-expression of laccase CueO from E. coli JM109 strain responsible for degradation of benzo [a] pyrene.…”

“…Results of the current study supported the findings of earlier researchers wherein, the above enzymatic pathways were reported to be active in several bacterial genera belonging to different classes viz., α-Proteobacteria (Brucella, Rhizobium, Sphingobium, Sphingomonas), β-Proteobacteria (Burkholderia sp. ), γ-Proteobacteria (Pseudomonas, E. coli, K. pneumoniae) (Akita et al 2016;Bugg et al 2011;Gaur et al 2018;Pandit et al 2016;Prabhakaran et al 2015;Tian et al 2014;Zeng et al 2011). Researchers are increasingly targeting new sources like marshy sediments, rain and tropical forest soils, and grass lands for isolating more potent aromatic and lignolytic communities.…”