Rhizobia amylase production using various starchy substances as carbon substrates

Abstract

Six isolates of indigenous rhizobia of Central Amazonia were screened for the production of amylases in liquid media using various starchy substances as carbon sources. All rhizobia strains could produce more extracellular protein, biomass and amylases with the different kinds of carbon substrates. Among the carbon sources tested maltose was the best substrate for protein and amylase production. In general, peach palm flour and corn starch (maizena ® ) were also considered to be good carbon sources for rhizobia amylases. On the other hand, the biomass production by the rhizobia isolates was higher in the presence of oat flour. INPA strain R-926 was a good amylase producer in maltose (1.94 U) and corn starch (0.53 U) media. INPA strain R-991 was also a good amylase producer in maltose (1.66 U) and corn starch (1.59 U) yielding significant extracellular amylase. Correlation analysis showed significant and positive relationships between rhizobia amylases and final pH (r = 0.49, P < 0.05), extracellular protein (r = 0.47, P < 0.47) and biomass production (r = 0.69, P < 0.01) in the maltose medium. The results obtained in this study revealed several Central Amazonian rhizobia strains as promising sources of amylase for biotechnological applications, especially in starch industry.

Partial characterization of amylases of two indigenous Central Amazonian rhizobia strains

“…INPA R-991 isolated from soils of the Central Amazonian floodplain. The rhizobial strains were identified by partial sequencing of the 16S rRNA gene (Oliveira et al, 2007). Stock cultures were maintained on extract-mannitol agar (YMA) slants (Vincent, 1970) at 4 o C. The medium used for enzyme production was composed of (g L -1 ): 10.0 maltose, 0.4 K 2 HPO 4 , 0.1 K 2 HPO 4 , 0.2 MgSO 4 .7 H 2 O, 0.1 NaCl and 0.4 yeast extract.…”

“…Nonetheless, studies on rhizobia amylases are still scarce. Recently, Oliveira et al (2006) reported the occurrence of extracellular amylases in rhizobia strains in solid and liquid media (Oliveira et al, 2007). The aim of this study was the production and characterization of extracellular amylases from two indigenous Central Amazonian rhizobia strains.…”

Isolation and Characterization of Bacillus Subtilis KC3 for Amylolytic Activity

“…They have opened new frontiers of many commercial biotechnological processes including renewable energy, pharmaceuticals, saccharification or liquefication of starch, detergent industries, warp sizing of textiles, fibres, paper industries, foodstuffs, baking, clarification of haze formed in beer or fruit juices and for pretreatment of animal feed to improve digestibility [1]- [6]. Amylases are known to be produced by a variety of bacteria and fungi and their applications at industrial level have stimulated interest to explore their amylolytic activity in several microbes to be used as bioresources [2], [7]- [9]. The horizon got further magnified with the discovery of new strains of microorganisms and development of more efficient production strategies because microbes have substantial potential to contribute to several commercial purposes.…”

Phenotypic diversity and amylolytic activity of fast growing rhizobia from pigeonpea &#91;Cajanus cajan (L.) Millsp.&#93;

“…The metabolic characterization of Brazilian rhizobial strains has shown a great versatility of their potential to other biotechnological applications than inoculant production, such as production of microbial biopolymers (2,8,9), and enzymes with industrial application (19,20,21).…”