The effect of substrate consumption on the increasing of biofloculans productivity and activity of cultivation by Alcaligenes latus

Abstract

Abstract The efficient technology cultivation is developed as a respond to the emergence of clean technology trend issue to produce biogically degraded product. This research aims to review the effect of sweet potato hydrolysis concentration on biofloculan cultivation productivity and its effect on flocculation activity. Cultivation starts from cell refreshment to propagation and inoculation into cultivation medium which has been sterilized. Enzymatically, the sweet potato starch hydrolyzate supernatant usage (S) as a cultivation medium is expected can substitute glucose (G) synthetic medium and able to increase bioflocculant activity and bioabsorbent formation, while the Nitrogen substrate usage from CSL (C) and yeast extract (Y) into the medium. Cultivation of Alcaligenes latus can stimulate the formation of acid biopolymers which have large molecular weights. Furthermore, made a notation like SC-10 which is a medium of glucose supernatant factor with Corn steep liquor (CSL) with an initial sugar concentration level of 10 g/l. Control process including the analysis of reduced sugar (RS) and nitrogen, viscosity, pH, measurement of dry cell weight (DC), and flocculation activity (AF) is conducted during cultivation. The research results indicates the usage of sweet potato supernatan hydrolysate is to subsitute the synthetic mediums due to its ability to increase biofloculan activity. The best medium for biofloculan cultivation is SC-10 with kinetic parameter μ, 0,0834 hours-1; Xmax,12,54 g/l; m, 0,641 and n, 0,0105 g product/g biomass/hours; α, 0,409 and β, 0,0006 g biomass/g substrate/ hours; Yp/s, 68%; Yx/s, 97%. There is no significant viscosity changes during cultivation so that it can not be used as a production index. Flocculation Activity resulting from the cultivation of SC-10 medium is the strongest process in forming flok-flok while SC-30 medium is the least.