Nitrogen sources on TPOMW valorization through solid state fermentation performed by Yarrowia lipolytica

This manuscript reports the valorization of two-phase olive mill waste (TPOMW) as raw material and carbon source for solid state fermentation using Yarrowia lipolytica as biocatalyst. Due to its chemical characteristics, a combination of different raw materials (TPOMW and wheat bran, WB) was evaluated and two distinct nitrogen sources were applied as supplementation for lipase production. A TPOMW/WB ratio of 1:1 and supplementation with ammonium sulfate was chosen as the best condition. The productivity in 24 h reached 7.8 U/gh and, after four days of process, only decreased about 35%. Process pH ranged from 5.5-5.9, remaining in an acid range. Thus, the successful use of TPOMW, a watery solid by-product with high content of lipids, as raw material for Yarrowia lipolytica growth and lipase production provided an environmental friendly alternative to valorize such waste.The authors kindly acknowledge the financial aid and research scholarships given by CAPES. Maria Alice Zarur Coelho thanks CNPq (Proc. 308890/ 2013-2)

Optimization of lipase entrapment in alginate gel bead for palm olein hydrolysis

Lipase from Pseudomonas sp. was entrapped by drop-wise addition of an aqueous mixture of alginate and the biocatalyst to hardening solution of CaCl2 for the purpose of palm olein hydrolysis. Effects ofimmobilization conditions including alginate concentration, CaCl2 concentration, enzyme concentration and bead size on immobilized yield, immobilized lipase activity and recovery of activity (specific activity ratio ofentrapped lipase to free lipase) were investigated. An increase in alginate concentration raised immobilized yield, but decreased immobilized lipase activity and recovery of activity. CaCl2 concentration in the testedrange of 50-200 mM had slight effects on immobilized yield, immobilized lipase activity and recovery of activity. In contrast to immobilized lipase activity, immobilized yield and recovery of activity decreased withincreasing enzyme concentration. With increasing bead size, immobilized lipase activity and recovery of activity decreased due to mass transfer resistance whereas immobilized yield was unchanged. The optimumcondition for lipase entrapment in alginate gel bead was alginate concentration at 2% (w/v), CaCl2 concentration at 100 mM, enzyme concentration at 30 U/ml and bead size at 2 mm. Under this entrapmentcondition, 8.11 U/ml of immobilized lipase was obtained with 95.2% of immobilized yield and 22.2% of recovery of activity

Turning waste into valuable products: utilization of agroindustrial oily wastes as the low-cost media for microbial lipase production

Abstract The cost-effective production of lipase by microorganisms are currently needed. The bioconversion of agro-industrial oily wastes as an alternative oily substrate for lipase production in the form of solid-state fermentation (SSF) or submerged fermentation (SmF) would hold a potential role in future biotechnology. There are some studies revealed that yeast, fungi, and bacteria are the choice for lipase production such as from the genera Aspergillus, Penicillium, Rhizopus, Candida, Geotrichum, Stenotrophomonas, Lasiodiplodia, and Yarrowia, as well as Staphylococcus, Burkholderia, Enterococcus, Pediococcus, Pseudomonas, and Bacillus utilizing several residues such as oil cakes and oily wastewater. In this review, the microbial lipase production conducted by many scientists utilizing agro-industrial oily wastes as the substrates is summarized.</jats:p

Metagenomic insights into bioaugmentation and biovalorization of oily industrial wastes by lipolytic oleaginous yeast Yarrowia lipolytica during successive batch fermentation

The lipolytic oleaginous yeast Yarrowia lipolytica was used in the bioaugmentation and biovalorization of oily industrial wastes during successive-batch fermentation. Five cycles of nonsterile successive batch fermentation with 70% medium replacement achieved the highest oil removal of 68.1 \ub1 5.60% and produced biomass and lipid yields of 0.213 \ub1 0.07 g/g-COD and 146.2 \ub1 46.5 mg/g-COD, respectively. The cell-bound lipase activity observed in the system was 170.74 \ub1 32 U/L. The auto-flocculation efficiency of the biomass was >90% within 60 Min. The microbial community changes between Y. lipolytica and indigenous microorganisms were monitored by metagenomic next-generation sequencing of internal transcribed spacer rDNA regions for yeasts and 16S rRNA gene for bacteria. Ylipolytica lipolytica was retained in the consortium together with other indigenous strains until the fifth cycle. Other minor oleaginous yeasts such as Kodamaea ohmeri and Candida tropicalis as well as polyhydroxyalkanoate-accumulating bacteria were found and are likely to have participated in lipid production. This study has shown the robustness of Y. lipolytica in nonsterile successive batch fermentation and its use could contribute greatly to the practical valorization of industrial wastes for lipids and lipases

Deploying two-stage anaerobic process to co-digest greasy sludge and waste activated sludge for effective waste treatment and biogas recovery

High-strength waste activated sludge (WAS) and greasy sludge (GS) were largely generated from canned tuna processing. This study reports the performance of the two-stage anaerobic process for co-digesting WAS and GS. Various WAS:GS mixing ratios of 0:100, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10, and 100:00 (volatile solids (VS) basis) were investigated in batch acidogenic stage at ambient (30 °C ± 3 °C), 55 °C, and 60 °C temperatures. Subsequently, the effluents from the first stage were used to produce methane in the second methanogenic stage at an ambient temperature. The highest methane yield of 609 mL CH4/g-VSadded was achieved using acidogenic effluents generated from a WAS:GS mixing ratio of 40:60 at an ambient temperature. The first-order kinetic constants (k) for the first (k1) and second (k2) stages were subsequently estimated to be 0.457 d−1 and 0.139 d−1, respectively. The obtained k constants were further used to predict the hydraulic retention time (HRT) for the two continuously stirred tank reactors (CSTR) in series. Consequently, the calculated 4-day HRT and 20-day HRT for 50-L CSTR1 and 250-L CSTR2, respectively, were used to operate the continuous two-stage process at an ambient temperature by feeding with a 40:60-WAS:GS mixing ratio. A satisfactory methane yield of 470-mL CH4/g-VS along with 75% chemical oxygen demand (COD) removal was generated. Furthermore, the predicted methane yield of 450-mL CH4/g-VS obtained from the simple kinetic CSTR model resembled the experimental yield with 96% accuracy. The obtained experimental results demonstrate that WAS and GS co-digestion could be successfully accomplished using a practical two-stage anaerobic process operated at an ambient temperature.No Full Tex