Bran Hydrolysate Research Articles

Antihypertensive Effect and Safety Evaluation of Rice Bran Hydrolysates from Sang-Yod Rice.

Rice bran hydrolysates contain highly nutritional proteins and beneficial phytochemicals. Sang-Yod rice bran hydrolysates (SRH) extracted from red pigmented rice is a rich source of nutrients and phenolic compounds. The present study evaluated the antihypertensive effect of SRH and its safety in Sprague-Dawley rats. Hypertension was induced in male rats by administration of L-NAME (50mg/kg/day) in drinking water for three weeks, and the antihypertensive effect of SRH was evaluated. Treatment of SRH (250 or 500mg/kg) significantly reduced arterial blood pressure and improved hemodynamic parameters. The antihypertensive effect was associated with decreased oxidative stress, suppressed p47phox NADPH oxidase expression, increased nitric oxide bioavailability and decreased angiotensin II level and ACE activity. The SRH was shown to be safe after feeding male and female rats with a rodent diet containing 1.5% SRH for 90days. Overall, these findings suggest that SRH is safe and may help to prevent hypertension.

Effect of nitrogen sources and neutralizing agents on D-lactic acid production from Kodo millet bran hydrolysate: comparative study and kinetic analysis.

D-lactic acid (DLA) serves as a key monomer enhancing both the mechanical and thermal properties of Poly(lactic) acid films and coatings, extensively used in the food packaging industry. Economically viable production of optically pure DLA by Lactobacillus delbrueckii NBRC3202 was achieved using a low-cost carbon source, Kodo millet bran residue hydrolysate (KMBRH) and nitrogen source (casein enzyme hydrolysate (CEH) resulting in a high DLA yield of 0.99gg-1 and KMBRH conversion to final product (95.3%). The optimum values for kinetic parameters viz., specific growth rate (0.11h-1), yield coefficient of biomass on KMBRH (0.10gg-1) and DLA productivity (0.45gL-1h-1) were achieved at 5gL-1 of CEH dosage under controlled pH environment. A comparative study and kinetic analysis of different neutralizing agents (NaOH, NH3, CaCO3 and NaHCO3) under pH controlled environment for KMBRH based DLA production was addressed effectively through bioreactor scale experiments. Maximum cell concentration (1.29gL-1) and DLA titer (45.08gL-1) were observed with NH3 as a neutralizing agent. Kinetic analysis of DLA production under different neutralization agents demonstrated that the logistic derived model predicted biomass growth, KMBRH consumption and DLA production efficiently (R 2 > 0.92).

Effect of rice bran hydrolysates on physicochemical and antioxidative characteristics of fried fish cakes during repeated freeze-thaw cycles

Rice bran hydrolysates (RBH) produced from hexane defatted rice bran using subcritical alkaline water extraction followed by enzymatic hydrolysis showed high protein and total phenolic contents and showed high antioxidant activity. FTIR results confirmed that RBH consisting of protein (amide I & II), saccharide, phenolic hydroxyl group and Maillard reaction products had antioxidant activity. Adding 1 and 2% RBH significantly reduced fat content in fried fish cakes by 20.9 and 29.3%, respectively, compared to the control. Lipid oxidation was significantly reduced when RBH or BHA/BHT was used. RBH at 2% was equally as effective as 0.02% BHA/BHT. RBH-treated fried fish cakes had higher concentrations of total phenolics (63.9 mg GAE/100 g sample) and showed the highest antioxidant activity (both DPPH• and ABTS• radical scavenging activity). This study showed that RBH can significantly improve the quality of fried cake products as it reduced fat uptake and effectively provided antioxidative protection. Consequently, RBH, as a natural alternative to synthetic antioxidants, might be used for extending the frozen shelf life of fried surimi seafood.

Valorization of food-waste hydrolysate by Lentibacillus salarius NS12IITR for the production of branched chain fatty acid enriched lipid with potential application as a feedstock for improved biodiesel

Oxidation stability and cold flow properties of biodiesel can be improved by using lipid with enriched branched-chain fatty acid (BCFA) as a feedstock. A halophilic bacterium was utilized for the production of BCFA enriched lipid from acid hydrolysate of food-waste. The maximum reducing sugar obtained by hydrolysis of wheat bran, rice bran, mango peel, and orange peel were 64.52 ± 0.57, 38.7 ± 0.58, 55.64 ± 1.14, 36.29 ± 0.54 g/L, respectively. On assessing these hydrolysates as feedstock for growth of halophilic bacterium Lentibacillus salarius NS12IITR at 10 g/L reducing sugar concentration, wheat bran hydrolysate was found to be best in-terms of sugar consumption (92%), lipid production (0.70 ± 0.029 g/L) and maximum branched-chain fatty acid methyl ester (FAME) (81 ± 4.72% of total FAME). At 20 g/L of reducing sugar concentration of wheat bran hydrolysate, the biomass and lipid yields were almost doubled. Efficient lipid extraction from cell, involving thermolysis at 85 °C and pH 2 along with osmotic shock resulted in isolation of 69% of total lipid.

Evaluation of various Bacillus coagulans isolates for the production of high purity L‐lactic acid using defatted rice bran hydrolysates

SummaryDefatted rice bran (DRB) constitutes an abundant by‐product stream, generated during rice milling and subsequent bran oil extraction. Enzymatic hydrolysis of starch and protein content in DRB was optimised in terms of solid loading. Among the four solid loadings evaluated (10%, 15%, 20% and 25%), the hydrolysate derived from 20% solids resulted in the highest concentration of glucose (82.3 g L−1) and free amino nitrogen (234.8 mg L−1). The fermentability of the hydrolysate was evaluated via screening of sixteen isolates. All the strains were able to grow and produce high purity L‐lactic acid, utilising the DRB as sole carbon and nutrient source. Among the studied strains, the Bacillus coagulans A107 isolate presented the most promising results in terms of final lactic acid concentration (75.9 g L−1), yield (0.90 g g−1) and productivity (2.7 g L−1 h−1). The results of this study indicate that DRB could be employed as an inexpensive, alternative substrate for L‐lactic acid production.

Controlling Lipid Oxidation and Volatile Compounds in Frozen Fried Fish Cake Prepared with Rice Bran Hydrolysate

ABSTRACTFried fish cakes formulated with (1) no antioxidant (control), (2) 1% rice bran hydrolysate (RBH), (3) 2% RBH, (4) 0.05% rosemary oil, and (5) 0.02% butylated hydroxyanisole/butylated hydroxytoluene (BHA/BHT) were investigated for their oxidation values following 0–9 freeze-thaw cycles. Both lipid oxidation and protein oxidation were significantly obstructed when RBH or BHA/BHT was used. RBH at 2% was equally effective as 0.02% BHA/BHT. Headspace solid phase microextraction (HS-SPME), which measures volatile compounds that determine lipid oxidation, demonstrated the effectiveness of RBH. The development of rancid volatile compound (i.e., hexanal) levels in fried fish cakes decreased during 0–9 freeze-thaw cycles. This study demonstrates that RBH is as an effective antioxidant comparable to commercial antioxidants (BHA/BHT) in frozen fried fish cakes. Consequently, RBH can be a consumer-friendly and natural antioxidant ingredient.

The production of hydrolysates from industrially defatted rice bran and its surface image changes during extraction.

This research employed a mild subcritical alkaline water (mild-SAW) extraction technique to overcome the difficulty of active compound extractability from industrially defatted rice bran (IDRB). Mild-SAW (pH 9.5, 130 °C, 120 min) treatment followed by enzymatic hydrolysis (Protease G6) was applied to produce rice bran hydrolysate (RBH). Response surface methodology was used to identify proteolysis conditions for maximizing protein content and ABTS radical scavenging activity (ABTS-RSA). Microstructural changes occurring in IDRB during extraction were monitored. The selected RBH was characterized for protein recovery, yield, antioxidant activities, phenolic profile and hydroxymethylfufural (HMF) content. Optimal proteolysis conditions were 20 mL kg-1 IDRB (enzyme/substrate ratio) for 6 h. Under these conditions, the yield, ABTS-RSA, ferric reducing antioxidant power and total phenolic content of the RBH were 46.1%, 294.22 µmol trolox g-1 , 57.72 µmol FeSO4 g-1 and 22.73 mg gallic acid g-1 respectively, with relatively low HMF level (0.21 mg g-1 ). The protein recovery was 4.8 times greater than that by conventional alkaline extraction. Its major phenolic compounds were p-coumaric and ferulic acids. The microstructural changes of IDRB confirmed that the mild-SAW/Protease G6 process enhanced the release of active compounds. The process of mild-SAW extraction followed by proteolysis promotes the release of active compounds from IDRB. © 2017 Society of Chemical Industry.

Enzymatic hydrolysis on protein and β-glucan content of Sang-yod rice bran hydrolysates and their anti-inflammatory activity on RAW 264.7 cells

Background: Research focusing on the improvement of the utilization of rice bran is increasing due to its nutritional properties. Several biological activities of rice bran hydrolysates and its constituents have been reported. Sang-yod rice, a local rice variety in Southern of Thailand, is a pigmented rice. Furthermore, its bran has high nutritive value and health beneficial components. Accordingly, there is growing interest in transforming this by-product into a functional food ingredient.Objective: To investigate the effect of enzymatic hydrolysis processes on the digestion of protein and β-glucan and evaluate anti-proinflammatory properties of selected hydrolysates on RAW 264.7 macrophage cells.Method: Sang-yod rice bran hydrolysates were obtained using a single or co-enzymatic hydrolysis process and sequential hydrolysis process using amyloglucosidase and protease G6. Effects of enzyme concentration (3-5% v/w) and hydrolysis duration (30, 60, and 120 min) on soluble protein and β-glucan contents of obtained rice bran hydrolysates were evaluated. The selected rice bran hydrolysates were evaluated for their cell viability and inhibition against NO and pro-inflammatory cytokines generation on RAW 264.7 mouse macrophage cell lines. Results: Protein content (0.59-3.37 %) of the rice bran hydrolysates (RBHs) was increased by increasing of enzyme concentration (3-5% v/w) and hydrolysis time (60-120 min). However, the β-glucan content (0.88-4.63%) of RBHs decreased with the increase of those parameters. The RBHs derived by the sequential process using 5% v/w enzyme concentration and 60 min hydrolysis time gave high protein (3.23%) and high β-glucan (4.02%) contents. The hydrolysates with high amount of protein and/or β-glucan contents demonstrated no cytotoxicity against RAW 264.7 cells at concentration range of 100-2,000 μg/ml. Additionally, they demonstrated NO inhibition and pro-inflammatory inhibition ranges of 49.09-71.63% and 9.37-71.96% respectively. Generation of TNF-α, IL-6, and IL-1β cytokines was inhibited differently by the selected RBHs. Conclusion: Pre-digestion of Sang-yod rice bran with amyloglucosidase followed with co-hydrolysis of amyloglucosidase and protease G6 of the sequential hydrolysis process was the most effective process to release β-glucan and protein from of rice bran. The hydrolysate obtained from the process using enzyme concentration at 5%v/w and 60 min hydrolysis duration of each stage had the highest soluble β-glucan and protein content. Moreover, the process provided the hydrolysates with potential anti-inflammatory properties on nitric oxide inhibition and pro-inflammatory cytokines inhibition on RAW 264.7 macrophage cell line. Keywords: Sang-yod rice, Rice bran hydrolysate, β-glucan, Enzymatic hydrolysis, Anti-inflammatory activity

Endocellulase Production by Cotylidia pannosa and its Application in Saccharification of Wheat Bran to Bioethanol

For efficient bioconversion of lignocellulosic materials to bioethanol, the study screened 19 white-rot fungal strains for their endocellulolytic activity and saccharification potential. Preliminary qualitative and quantitative screening revealed Cotylidia pannosa to be the most efficient endocellulase producing fungal strain when compared to the standard strain of Trichoderma reesei MTCC 164. Ensuing initial screening, the production of endocellulase was further optimized using submerged fermentation to recognize process parameters such as temperature, time, agitation pH, and supplementation of salts in media required for achieving maximum production of endocellulase. The strain C. pannosa produced the maximum amount of endocellulase (8.48 U/mL) under submerged fermentation with wheat bran (2%) supplemented yeast extract peptone dextrose (YEPD) medium after an incubation time of 56 h at 30 °C and pH 5.0 at an agitation rate of 120 rpm with a saccharification value of 50.5%. The fermentation of wheat bran hydrolysate with Saccharomyces cerevisiae MTCC 174 produced 4.12 g/L of bioethanol after 56 h of incubation at 30 °C. The results obtained from the present investigation establish the potential of white-rot fungus C. pannosa for hydrolysis and saccharification of wheat bran to yield fermentable sugars for their subsequent conversion to bioethanol, suggesting its application in efficient bioprocessing of lignocellulosic wastes.

Release of sugar by acid hydrolysis from rice bran for single cell oil production and subsequent in-situ transesterification for biodiesel preparation

Biodiesel is one of the promising alternative biofuel to petro-diesel. Efficient and effective utilization of low value feedstock is required to meet the current demand on biodiesel. Rice bran is a byproduct of rice milling that contains significant amounts of sugar (~48%) and lipids (~14%). Immediate recovery of the lipids is uneconomical owing to its moderate lipid content. In this work, hydrolysis of raw rice bran was firstly carried out to concentrate lipids in the hydrolyzed bran to ~42%. Hydrolysis of rice bran using 2% sulfuric acid at 90°C for 3.5h with stirring at 300rpm resulted in hydrolysates containing ~41g/L sugars and 3.75g/L proteins. Rice bran hydrolysate (RBH) obtained was further utilized as growth media for Lipomyces starkeyi, an oleaginous yeast. Lipid content of 40 to 65% can be achieved, suggesting the potential of using RBH in single cell oil production. Composition of microbial oils obtained was similar to that of vegetable oils, which may potentially be adopted as a feedstock for biodiesel production. Furthermore, dried hydrolyzed rice bran was subjected to in-situ (trans)esterification with methanol under subcritical condition which resulted in high FAME yield (87.81%) and conversion (94.82%). This work demonstrated the maximized utilization of rice bran in the production of hydrolysate for fermentation and as biodiesel feedstock. This is to further support the use of direct acid hydrolysis of biomass in the recovery and use of its content of sugars and lipids.

Corn bran bioprocessing: Development of an integrated process for microbial lipids production

This study investigated the potential of corn bran as a feedstock for microbial lipid production using oleaginous yeast, Trichosporon oleaginosus ATCC20509. Different conditions (solid loading of biomass, acid loading, and pretreatment duration) were applied to optimize pretreatment processes using the Box-Behnken design. The highest sugar yield of 0.53g/g was obtained from corn bran hydrolysates at a pretreatment condition of 5% solid loading and 1% acid loading for 30min. Compared with synthetic media, up to 50% higher lipid accumulations in T. oleaginosus were achieved using corn bran hydrolysates during fermentation. Also, the direct effect of pretreatment condition on the lipid accumulation of T. oleaginosus was investigated using response surface methodology (RSM). Solid loading of biomass during the pretreatment process significantly affected the fermentation process for lipid accumulation of T. oleaginosus. The RSM model can provide useful information to design an integrated bioconversion platform.

Development of media to accelerate the isolation of indigo-reducing bacteria, which are difficult to isolate using conventional media.

Indigo-reducing bacteria perform natural fermentation in indigo fermentation fluid. Owing to the stochastic nature of the process, the constituent in indigo fermentation fluid differ depending on the prepared batch and fermentation period. To identify new indigo-reducing bacteria, isolation of the bacteria is indispensable. However, isolation of indigo-reducing bacteria is difficult because conventional media are often unsuitable to isolate these slow-growing bacteria that also exist in low numbers. Hydrolysates of polysaccharides and mixtures of plant base constituents are candidates to accelerate the isolation of indigo-reducing bacteria that cannot be isolated using conventional media. In this current study, wheat bran hydrolysate and composted indigo leaves (sukumo) were used as ingredients in the fermentation fluid in the selective medium for indigo-reducing bacteria in anaerobic culture. The results suggested that obligate and oxygen-non-metabolizing facultative anaerobes are difficult to isolate using conventional media, whereas oxygen-metabolizing facultative anaerobes, relatively rapid-growing and major bacterial strains are relatively easy to isolate. Media containing sukumo hydrolysate facilitated the isolation of novel species of Bacillus pseudofirmus-related strains, whereas media containing wheat bran hydrolysate facilitated the isolation of Amphibacillus spp. (including new species). Seven species (including two new species) of indigo-reducing bacteria were isolated using wheat bran hydrolysate-containing media, whereas six species (including three new species) of indigo-reducing bacteria were isolated using media containing both wheat bran and sukumo hydrolysates. These newly developed culture media will facilitate the isolation of unknown bacteria in indigo fermentation and in environments similar to indigo fermentation fluid.

Production of itaconic acid by biotransformation of wheat bran hydrolysate with Aspergillus terreus CICC40205 mutant

The replacement of the carbon source in the microbial production of itaconic acid (IA) with economic alternatives has attracted significant attention. In this study, an Aspergillus terreus CICC40205 mutant was used to increase the IA titer and decrease the citric acid titer in the wheat bran hydrolysate compared with the parental strain. The results showed that the IA titer was increased by 33.4%, whereas the citric acid titer was decreased by 75.8%, and were in accordance with those of the improved pathway of co-metabolism of glucose and xylose according to the metabolic flux analysis. Additionally, the maximum IA titer obtained in a 7-L stirred tank was 49.65gL−1±0.38gL−1. Overall, A. terreus CICC40205 showed a great potential for the industrial production of IA through the biotransformation of the wheat bran hydrolysate.

Purification of pentoses from hemicellulosic hydrolysates without neutralization for sulfuric acid recovery

Abstract The agro-industrial sector generates large amounts of coproducts such as lignocellulosic biomass which could be valorized into many chemicals and bio-based intermediates (sugars, paper pulp, surfactants, polymers or bioethanol). However, in the case of biomass hydrolysis by diluted sulfuric acid, current downstream processes involve a partial or complete neutralization which are not satisfactory for economic and environmental reasons. This work presents a purification process of pentoses from hemicellulosic hydrolysates without neutralization for sulfuric acid recovery. Compared to conventional processes, less energy, water and chemicals are required. Very promising results were obtained at pilot scale with 100 L of wheat bran hydrolysates. The process is based on the combination of ultrafiltration, conventional electrodialysis and ion-exchange. Ultrafiltration with a 10 kDa organic membrane totally removed harmful macromolecules which precipitate during electrodialysis operation because of pH rise. Till a volumetric concentration factor 3.6, the average flux kept good for industrial application (27 L·h−1·m−2). However suspended materials have to be filtered before ultrafiltration. Besides, a 2.5 diafiltration is required to recover most of sugars (99%). Then conventional electrodialysis was performed to recover most of sulfuric acid (80%). The average faradic yield was quite good (80%) and the specific energy consumption of the electrodialysis stack was quite interesting (1.1 kW h per kg of H2SO4 recovered and 8.4 kW h per m3 of hydrolysate). Finally, the complete demineralization (conductivity

Production of polyhydroxybutyrate from wheat bran hydrolysate using Ralstonia eutropha through microbial fermentation

The increasing global demand for sustainable resources necessitates the complete utilization of feedstock. Wheat bran consists of significant amount of cellulose and hemicellulose which can be used as a renewable resource for production of fermentable sugars. In this study, alkaline pretreated wheat bran was enzymatically hydrolyzed using cellulase of Trichoderma reesei (37 FPU/g) and β - glucosidase of Aspergillus niger (50 CBU/g). Among the nitrogen sources tested, ammonium sulphate was identified as best nitrogen source for the production of polyhydroxybutyrate (PHB). The overall sugar concentration was about 62.91g/L with the corresponding sugar yield of 629.1mg/g wheat bran and the sugars released were mainly composed of glucose (48.35g/L) and xylose (14.56g/L). The PHB producing mutant strain, Ralstonia eutropha NCIMB 11599 grown in wheat bran hydrolysate produced cell density, PHB and yield of 24.5g/L, 62.5%, and 0.319g/g sugar respectively, with a productivity of 0. 0.255g/L/h. Thus, the results suggested that the wheat bran could be a potential alternative feedstock as it does not require any detoxification due to less inhibitory compounds for production of high cell density with significant amount of polyhydroxybutyrate.

Maximized Utilization of Raw Rice Bran in Microbial Oils Production and Recovery of Active Compounds: A proof of concept

Lignocellulosic biomass is currently considered as one of the promising feedstock for petroleum diesel alternative, together with single cell oils. Rice bran, which is a very abundant waste especially in Asia, could be utilized better than just as cattle feed. Dilute acid hydrolysis using 3 % H2SO4 at 90 °C was found to be able to maximize the sugar produced from raw rice bran without prior oil extraction (TRS = 54.91 g/L). Activated carbon was used for removing most furan inhibitors from rice bran hydrolysate (RBH) after hydrolysis and resulted in a TRS of 50.10 g/L. RBH was then neutralized using calcium hydroxide and diluted to a TRS concentration of 30 g/L. RBH was used to culture Yarrowia lipolytica PO1g, resulting in a comparable results of lipid content to that cultured in complex medium (YPD). The highest crude lipid content obtained from Y. lipolytica cultivated in RBH with addition of 10 g/L yeast extract was 23.94 % (biomass = 14.3 g/L), while the optimum result obtained using YPD was at a C/N ratio of 9.5 (biomass reached 14.7 g/L) and crude lipid content was 28.42 %. Furthermore, lipid and γ-oryzanol can be recovered after dilute acid hydrolysis.

Purification of pentoses from hemicellulosic hydrolysates with sulfuric acid recovery by using electrodialysis

Abstract The valorization of lignocellulosic biomass as a renewable carbon source is growing in chemical industries, particularly in the agro-industrial sector. Many chemicals compounds and bio-based intermediates can be produced but their production needs to be more cost-competitive. The valorization of pentoses in hemicellulosic hydrolysates, obtained by using dilute sulfuric acid, is of growing interest. However, current downstream processes which involve a partial or complete neutralization of the acid are not satisfactory for economic and environmental reasons. This work presents a method of purification of pentoses with sulfuric acid recovery which reduces water and chemicals consumptions. The results obtained at the laboratory scale with wheat bran hydrolysates are very promising. The process is based on the combination of ultrafiltration, conventional electrodialysis and ion-exchange. A special organic UF membrane (Alpha Laval - UFX10pHt), resistant to acidic conditions, removed totally macromolecules which can damage the electrodialysis unit by precipitation, with good mean permeate flow rate (24 L h −1 m −2 till VCF = 4.4). Then, conventional electrodialysis was performed to recover most of sulfuric acid ( > 80%) without losing sugars ( 2 SO 4 recovered and 4.2 kWh per m 3 of hydrolysate). Finally, the complete demineralization (conductivity −1 ) and discoloration (420 nm absorbance

High and Rapid L-lactic Acid Production by Alkaliphilic Enterococcus sp. by Adding Wheat Bran Hydrolysate

Two strains of alkaliphilic lactic acid bacteria, L-120 and AY103, which can produce L-lactic acid extensively, were isolated during trials of L-lactic acid production under unsterilized conditions at pH 9. Strains L-120 and AY103 are similar to Enterococcus casseliflavus and Enterococcus faecalis, respectively, as determined by 16S rRNA gene sequencing. It was found that wheat bran hydrolysate (1.5 or 3.0% dry w/v) strongly stimulates the production of lactic acid in both strains. Strain L-120 produced 149 g L-1 L-lactic acid at 35°C under pH 9 from 180 g L-1 glucose with the production rate of 3.9 g L-1 h-1. Strain AY103 produced 153 g L-1 L-lactic acid from 180 g L-1 glucose with the production rate of 4.2 g L-1 h-1. Both strains produced high-optical-purity (100%) L-lactic acid. In addition, strain L-120 produced 12% (w/v) L-lactic acid from degraded inedible materials, i.e., rice straw and soy bean curd refuse, within 72 h under unsterilized conditions. The obtained results indicate that these two strains are very useful for Llactic acid production with the advantages of high productivity and rapid production with reduced costs of product purification, raw materials and fermenter sterilization.

Iron-Binding Capacity of Defatted Rice Bran Hydrolysate and Bioavailability of Iron in Caco-2 Cells.

The present study was aimed at utilizing defatted rice bran (DRB) protein as an iron-binding peptide to enhance iron uptake in humans. DRB samples were treated with Alcalase and Flavourzyme, and the total extractable peptides were determined. Furthermore, the iron-binding capacities of the DRB protein hydrolysates were determined, whereas iron bioavailability studies were conducted using an in vitro digestion and absorption model (Caco-2 cells). The results showed that the DRB protein hydrolysates produced by combined Alcalase and Flavourzyme hydrolysis had the best iron-binding capacity (83%) after 90 min of hydrolysis. The optimal hydrolysis time to produce the best iron-uptake in Caco-2 cells was found to be 180 min. The results suggested that DRB protein hydrolysates have potent iron-binding capacities and may enhance the bioavailability of iron, hence their suitability for use as iron-fortified supplements.

Production of single cell oil from Lipomyces starkeyi ATCC 56304 using biorefinery by-products

Single cell oil (SCO) is a valuable noncrop-based renewable oil source. Hemicellulose derived sugars can be utilized to produce SCO using the oleaginous yeast Lipomyces starkeyi ATCC 56304. Bran by-products were tested as hemicellulose-rich feedstocks for the production of SCO. Whole and destarched corn and wheat bran hydrolysates were produced using hydrothermal and dilute sulfuric acid (0%, 0.5%, 1.0%, v/v) pretreatment along with enzymatic hydrolysis. Whole bran hydrolysates produced from hydrothermal pretreatment generated the highest average oil yields of 126.7 and 124.3mgoil/g sugar for both wheat and corn bran, respectively. 1.0% acid pretreatment was effective for the destarched bran generating a hemicellulose hydrolysis efficiency of 94% and 84% for wheat and corn bran, respectively, resulting in the highest oil yield of 70.7mgoil/g sugar. The results indicate pretreated corn and wheat bran hydrolysates can serve as viable feedstocks for oleaginous yeast SCO bioconversion.