Whole genome sequence of Serratia marcescens 39_H1, a potential hydrolytic and acidogenic strain Linda U. Obi a,b , Memory Tekere a , Ashira Roopnarain b , Tomasz Sanko c , Tawanda E. Maguvu c , Cornelius C. Bezuidenhout c , Rasheed A. Adeleke b,c, * a Department of Environmental Sciences, University of South Africa, Johannesburg, South Africa b Microbiology and Environmental Biotechnology Research Group, Institute for Soil, Climate and Water, Agricultural Research Council, Arcadia, 0083, Pretoria, South Africa c Unit for Environment Sciences and Management, North-West University (Potchefstroom Campus), Potchefstroom, South Africa A R T I C L E I N F O Article history: Received 21 May 2020 Received in revised form 27 September 2020 Accepted 9 October 2020 Keywords: Serratia marcescens Biogas Hydrolysis Whole genome sequence Plant-growth-promotion A B S T R A C T Here, we report a high quality annotated draft genome of Serratia marcescens 39_H1, a Gram-negative facultative anaerobe that was isolated from an anaerobic digester. The strain exhibited hydrolytic/ acidogenic properties by significantly improving methane production when used as a single isolate inoculum during anaerobic digestion of water hyacinth and cow dung. The total genome size of the isolate was 5,106,712 bp which corresponds to an N50 of 267,528 and G + C content of 59.7 %. Genome annotation with the NCBI Prokaryotic Genome Annotation Pipeline (PGAP) predicted a total of 4,908 genes of which 4,755 were protein coding genes; there were no plasmids detected. A number of genes associated with hydrolytic/acidogenic activities as well as other metabolic activities were identified and discussed. © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). 1. Introduction Biogas production from substrates such as water hyacinth and cow dung is an effective and environmentally friendly means of managing these waste streams. Water hyacinth is a complex lignocellulosic biomass that is rich in cellulose and hemicellulose and is therefore a potential substrate for biogas production [1]. However, the recalcitrant properties of the water hyacinth is an important challenge during the hydrolytic phase of anaerobic digestion (AD) [2]. Hydrolysis is the rate-limiting phase of AD of lignocellulosic substrates as insolubility of cellulose is the basis of its recalcitrance. This is as a result of the crystalline structure of cellulose fibres that are bound by β-1,4-glycosidic linkages [3]. The β-1,4-glycosidic linkages limit or inhibit the depolymerisation of cellulose hence the need for enhanced hydrolysis and subsequent acidogenic, acetogenic and methanogenic reactions to produce biogas. The need to facilitate the process and improve biomethane production through an existing effective and eco-friendly technol- ogy known as bioaugmentation with bacteria is imperative [4]. Bioaugmentation will assist in eliminating some expensive and not so eco-friendly pretreatment processes. Bioaugmentation is the addition of specialised actively growing pure or mixed cultures to the indigenous microbial community of anaerobic digesters in order to enhance microbial activity and improve degradation of organic wastes [5–7]. Bioaugmentation with hydrolytic bacteria seeks to boost the digestion of lignocellulosic substrates through the activities of inoculated bacteria. These bacteria possess active enzymes such as cellulases, β-glucosidases, acetate kinases and lactate dehydrogenases that are encoded by specific genes. Such enzymes are associated with depolymerisation of cellulose (etc.) via hydrolysis and acidogenesis [8]. Both pure and mixed cultures have been employed in bioaugmentation studies [9, 10]. Suitable bioaugmentation with pure hydrolytic/acidogenic bacteria could mitigate the challenges of recalcitrant nature of lignocellulosic biomass through facilitation of hydrolysis and subsequent acido- genesis. Improved hydrolytic/acidogenic rate can increase the production of methane from water hyacinth during AD. In this study, a high quality annotated draft genome sequence of Serratia marcescens 39_H1 is reported and observed hydrolytic/acidogenic phenotypic characteristics of the isolate was correlated to its genotype. Moreover, the potential application of the strain to promote plant growth was explored from the genotypic angle. Similarly, the potential dangers the strain may pose were also discussed as the Serratia species are known to be opportunistic pathogens. * Corresponding author at: Unit for Environment Science and Management, North-West University (Potchefstroom Campus), Potchefstroom, South Africa. E-mail address: rasheed.adeleke@nwu.ac.za (R.A. Adeleke). https://doi.org/10.1016/j.btre.2020.e00542 2215-017X/© 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Biotechnology Reports 28 (2020) e00542 Contents lists available at ScienceDirect Biotechnology Reports journa l homepage: www.elsevier.com/locate/btre