OPTIMIZATION OF BIOFLOCCULANT PRODUCTION BY Bacillus spp. FROM SUGARCANE CROP SOIL OR FROM SLUDGE OF THE AGROINDUSTRIAL EFFLUENT

Abstract

Biological flocculants are advantageous due to their biodegradability and safety to living beings. In this work, four bacterial strains, isolated from sugarcane cropped soil (Bacillus megaterium LBPMA-APFSG3Isox and B. toyonensis LBPMA-ACOPR1.Isox) and sludge of an agroindustrial effluent (B. pumilus LBPMA-BLD07 and B. thuringiensis LBPMA-EFIII), were studied. It was found that all of them secreted bioflocculants, at 37 ± 1 °C, with no pH changes over time and the flocculant activity increased during the time course of incubation. These results stimulated the optimization of the culture conditions to improve flocculation rates, such as the pH, nitrogen sources and carbon. For B. toyonensis LBPMA-ACOPR1.Isox and B. thuringiensis LBPMA-EFIII, the best pH for the bioflocculant production was 5.0. Sucrose and maltose were the best sources of carbon, while urea was the preferred source of nitrogen for two of the tested isolates (B. pumilus LBPMA-BLD07 and B. toyonensis LBPMA-ACOPR1.Isox), followed by (NH 4)2SO 4 (B. megaterium LBPMA-APFSG3Isox) and peptone (B. thuringiensis LBPMA-EFIII). The FTIR-ATR spectra of each extracted material responsible for the flocculant activities of the strains displayed carboxyl, hydroxyl and methoxy functional groups characteristic of polysaccharides.

Isolation and Identification of Bioflocculant-Producing Bacteria From Cassava Cultivated Soil of Viet Nam

“…AEMREG7 [25]. Likewise, Gouveia et al (2019) also reported that B. thuringiensis LBPMA-EFIII, B. toyonensis LBPMA-ACOPR1 Isox and B. megaterium LBPMA-APFSG3 Isox achieved their MFA 33 %, 21 % and 34 %, respectively, after 24 hrs of incubation, while B. pumilus LBPMA-BLD07 achieved MFA was 57 % after 72 hrs of incubation [28]. The results of our study showed that the strain of Enterobacter sp.…”

“…Gouveia et al also reported that sucrose was the most favorable carbon source for bioflocculant production by B. megaterium LBPMA-APFSG3Isox, and B. toyonensis LBPMA-ACOPR1.Isox, respectively, with 41 % and 39 % bioflocculating activity after 24 hrs. For B. pumilus LBPMA-BLD07 and B. thuringiensis LBPMA-EFIII, maltose was the best source of carbon to stimulate this bioflocculant activity (13 % and 25 %, respectively) [28].…”

“…Cultural temperature for maximum extracellular polysaccharide of Halobacillus trueperi AJSK [31] and Bacillus subtilis [32] was 35 o C, while the optimal flocculant production temperature for Citrobacter koseri has been reported was 30 o C [6]. According to Salehizadeh and Shojaosadati [33] and Zhang et al [34] the enzymes which were responsible for bioflocculant production were activated in a temperature range between 25 o C and 37 o C. The study of Gouveia et al [28] also showed that 37 o C was the optimal temperature for the growth as well as for the bioflocculant production of the B. pumilus LBPMA-BLD07, B. thuringiensis LBPMA-EFIII, B. toyonensis LBPMA-ACOPR1 and B. megaterium LBPMA-APFSG3.…”

Isolation of a Marine Bacterium and Application of Its Bioflocculant in Wastewater Treatment

“…There was maximum flocculating activity observed when urea was utilized as the nitrogen source, implying that urea effectively stimulated the growth of B. subtilis CSM5 and bioflocculant production. Urea was found to promote bioflocculant production of other Bacillus species such as Bacillus pumilus LBPMA-BLD07 and Bacillus toyonensis LBPMA-ACOPR1.Isox [37].…”