Abstract
This study screened four Rhizopus species as biosurfactant producers using different markers. First of all, Rhizopus spp. UCP 1607 was identified as Rhizopus arrhizus by morphological and molecular methods. The production of biosurfactant/bioemulsifier was investigated by submerged fermentation using soybean post-frying oil (5% v/v) and sodium glutamate (1% w/v) medium. The primary markers’ hemolysis and parafilm M tests showed that R. arrhizus UCP1607 strain exhibited higher hemolytic activity (49 mm of clear zone) on sheep blood agar and a larger drop diameter (12 mm) on parafilm hydrophobic surface. The experimental results showed the most promising biosurfactant production by R. arrhizus UCP 1607 strain led to a reduction of surface tension (31.8 mN/m) and the diameter of the oil-spreading covered an area of 66.4 cm2. The strains Rhizopus microsporus var. chinensis UCP1296, R. microsporus var. microsporus UCP1304, and R. arrhizus UCP1607 were capable of forming stable emulsions corresponding to 91.7, 94.8, and 82.6%, respectively in crude oil. Key words: Tensio-active agent, bioemulsifier, screening of Rhizopus strains, submerged fermentation.
Highlights
Caatinga is a biome that comprises an extensive semiarid area of 969.589,4 km2, located in the Northeast of Brazil
Rhizopus strains from the Caatinga soil used were: Rhizopus arrhizus var. arrhizus UCP 1295 and Rhizopus microsporus var. chinensis UCP 1296 and var. microsporus, UCP 1304 and were kindly provided by the culture collection, UCP (Catholic University of Pernambuco), Recife-PE, Brazil which is registered in the World Federation for Culture Collections (WFCC)
Four biosurfactant/bioemulsifier-producing strains were isolated from Caatinga soil of Brazil, namely R. arrhizus var. arrhizus UCP 1295, R. microsporus var. chinensis UCP 1296, R. microsporus var. microsporus UCP 1304 and Rhizopus spp
Summary
Caatinga is a biome that comprises an extensive semiarid area of 969.589,4 km, located in the Northeast of Brazil. A prominent feature of the semi-arid region of Caatinga is the climate markedly characterized by severe environmental conditions where high temperatures with the minimum above 15°C and the maximum around. 40°C, intense insolation, scanty water resources, and the annual rainfall in the area is estimated to be lower than 1000 mm, leading to prolonged periods of serious drought. The predominantly shallow soils present low natural fertility (Menezes et al, 2012; Silva et al, 2015). These environmental conditions of the semiarid region of Caatinga biome have a direct influence on soil microbial life. Studies aiming to explore the biotechnological potential of genus Rhizopus have demonstrated that species of this genus are able to produce different types of compounds of an enormous industrial importance, namely enzymes (Freitas et al, 2014), organic acids (Abe et al, 2007), chitin, and chitosan (Berger et al, 2014) including biosurfactant (Freitas Silva et al, 2012)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
