Biochemical and molecular identification of newly isolated pigmented bacterium and improved production of biosurfactant

Abstract

A novel bacterium pigmented isolate from Caatinga soil was characterized by biochemical and molecular assays, as well as, by rep-polymerase chain reaction (PCR) and 16S rDNA sequencing, and was identified as Serratia marcescens based on 99% of similarity. The identity of the sequences were compared by pairs of critical species of S. marcescens found in National Center for Biotechnology Information (NCBI) with a 96% homology of the isolated species to species database. The wild strain was able to produce biosurfactant (BS) using cassava (Manihot esculenta Crantz) wastewater, with addition of lactose, and corn oil, according to full factorial design 2 3 , at 28°C, and static condition. The net liquid metabolic reduced the surface tension of the water from 70 to 30.60 mN/m during the stationary phase (assay eight constituted by 6.0% cassava wastewater, 1.0% lactose and 7.5% corn oil), and produced emulsifier agent (4.012 UEA) at the same condition. This study identified the pigmented bacterium as new strain of S. marcescens, and showed it has potential to promote both emulsions formation and surface tension reduction in cassava wastewater (6.0%), lactose (1.0%) and corn oil (7.5%) proved as an alternative economical medium for commercial biosurfactant processes.

Sustainable biosurfactant produced by Serratia marcescens UCP 1549 and its suitability for agricultural and marine bioremediation applications

“…Previously, Araújo et al [25] used the same substrates and FFD for the production of biosurfactant by S. marcescens UCP 1549, but in static conditions, and they found the best results in condition 8, with reduction on surface tension to 30.60 mN/m. Highest tensioactive activity detected in current study in flasks with agitation can be linked to the physiological function of the biosurfactants.…”

“…In other hand, it was ratified the suitability of CWW as low-cost substrate for biosurfactant production. Commonly, it is used as nitrogen source, because it has a high presence of nitrogen in its composition [8, 25, 33, 34] (see Additional file 1: Table S1). Earlier, Ferraz et al [33] showed the ability of the biosurfactant produced by S. marcescens to reduce water surface tension of 72–28 mN/m using CWW as substrate.…”

“…Serratia marcescens UCP 1549, originally isolated and identified by Araujo et al [25] was kindly provided by the Culture Collection of the Catholic University of Pernambuco, Recife, Brazil, registered in the World Federation for Culture Collection (WFCC). The bacterium was maintained in Luria-Bertani (LB) solid medium (tryptone 10 g/L, yeast extract 5 g/L, NaCl 10 g/L and agar 15 g/L) at 5 °C.…”

“…Over the last years, several studies have reported the production of biosurfactants by S. marcescens strains using a variety of hydrophilic and hydrophobic substrates [21–24]. However, researches focusing on the use of agro-industrial waste are still few and they have been carried out by our research group [8, 25]. In addition, the toxicity of this secondary metabolite has only been tested in mice [26], and considering its potential for environmental application, further studies are needed.…”

Advancements in biosurfactant production using agro-industrial waste for industrial and environmental applications

“…If this trash is not managed well, it may cause problems for the environment. Nonetheless, creative methods have surfaced to transform this waste into useful goods, such as the synthesis of biosurfactants ( Helvia et al, 2017 ). Fruit peels, pulps, and seeds are among the many waste products produced by the fruit processing industry.…”