Production of Single cell protein from indusrial wastes

Abstract

Selection of a suitable microbi,1 culture and choice of sobotrE .:,e cnd.heir characterization are the two main prer-quisit.; of an Pconomical process. Yeasts capable of assimilating industrial lostris as thp sol source of crrbon were isolated from a wide variety of nt,ural sources during investigation on yeast production by enrictIl nt culture techniques and were purified by conventional streak method. icolaed yeast strains along with stock cultures u-re tested for th-Ar affinity towards industrial waste's such as k- roc -n,: oil enc.: Ci2sel oil of vtroleum fractions, sulfite waste li-uors, hydrol or maize ' ;%sr' and molasses ES col,- source of ccrbon. During cultivation of yeasts on the above mentioned su'ietreten, growth parameters such as substrate end N2 conc.nt . ion both quantitative PS well as quanta:Ave, were s';udied. Their influcnce on the biomass formationn, End quality of biomass hcs beon reported. pert from substrata and N cone-mtration special cl:;,,gelis has boon !liven to the availebilitt, of Emil n and its inflikino on yi-ld of biomass. Taxonomic-1 atudins revealed that these new sixteen isr'1,-tes included one strain of SocchEromyces corovisise, fivev. of Axhis membrammfaciens, two of i:]rneids tronicslin, four or C. goilliermondii, tic of lam. ruuosa, one of C. porapsilseis nrd zin. of .!hodotorula mucilaninosa. Thase industrial wastes were analysed chemically end ihL,o UJ--d i. a 50112 source of carbon. After the characterization of cultures and substrate come most important step is the fernontatian stage in the production of LI:Ingle Cell Protein (`MCP). Growth parameters such as medium composition, carbon and nitrunen cnncentrations, pH, temperature rnd supply or oxygen have been studied in shank flask experiments. The growth of Crmaida parapsilosis (H-D5) was much faster than that of Kerosene nil. Iloximum cell concrntration of 8.1 q/1 wee obs‘rvA in case of (NH4)2504 when compared to 7.2 end 6.4 al with NH4C1 and rIH4NO 3 respectively while studyinr influence of eiff r-nt nitrogen sources on the nrnuth or Candida lipnlytic uo±nn Ass'.1 oil as the sole source of carbon. Effect or oxygen availability nn the growth of Candida prrrpsilosis (H-D5) using diesel oil as the sole source of carbon showed a remarkable increase in biomass synthesis with a correspsndinn incrersu in the availability of oxvnen to the culture broth and thus resulted in bettor utilization of the substrate. The biomass obtaf,ned in sulfite waste liquor (;;'UL) fr.::entrtion were 3.4, 2.8 and %4 g/1 respectively in cane orAU) mItol'iaCendidarunosa(01 0.troriicalis(83)and C. parapsilosis (H-135) ifel,'n the inocAAm S1Z2 was 0.8 01. The incrm-se in inoculum siza upto .4 g/1, improved the biomass formation from 3.4 to 16.0 n/l, 2.3 to 14. n/1 and ".4 to 11.8 0/1 respectively, Ciom'ss formed rangld betu2en 41.3 to 42,5 ';; protein and 6.0 to 7.0 lipid. Maximum biomass formation was obsarved in Medium II when compored to Medium I while cultivating Candide ru, nsa (A) in different concentration of SUL. Effect of different conc%ntrations of NH 4C1 on the growth of C. a_2222 (A) usinr maize Igurl as the sole source of carbon showed that maximum biomass formation was obtained (12.72 g/ 1) when nitronon level was 4 p/1. Biomass was found to contain 37.5 5 and 35 5 protein in cnse of molaos:s and dlucoce experiments with Rhodotorula elutinis when the lipids ware 22 5 end 48.5 T;respectively. i Biomass formation was incronsad from 5.8 to 16.3 n/1 aft,r T-JJ hrn uhila cultivating C. runosa with 6 5 molauses. The vild of biomass was calculated to be 50 on the basis of sunar consum,d and protein content was 45.4 5. E:-IT-12dinq scale up studies with laboratory scale fermentors, the followinn experiments were carried out in 4 1 and 60 1 orkinn volume fermentors. Botch cultivation of Candida lipolvtica was cerri.ld out in 4 1 working volume formantor using; diesel oil as carbon source. EILLIess increased from 1.14 to 9.85 g/1 afthr 96 hrs.Tha hiomass formation was observed uhi1,2 cultivating Cantlida r! (A) A) and Modotorula qlutinis (R 44 ) with 6 maize iguri in a 3.5 1 working volume and found to be 9.5 and 11.5 g/1 respectively after 120 hrs. Yield HES calculated to On 46 ' on the besia of sugar consumed. Effect of different concentrations of maize 'our' on thus growth of Candida runos2 under constant aeration (11/1/min) shuw d th t uf..th the increase in sugar concentration in ,,ha rindium, vi ld of biomass is decreasing. Biomass increased from 2.0 to 20.8 g/1 irt..2-1! 96 hrs while cultiv:tinn C. rugosa using molassr,s (4 sugar cant c) in a 60 1 working volume firmuntor. gardinq quality of biomass obtainud from hvflro=bon End .1olassas expc:rim,..nte was analysed for protein, lipid, RNA and som- 'essential amino aciCs. Th'. amino wit: p:ofil: of these yeasts protr,in indica:sae that it could serve as a good source of food era; fad protein