Glycerol Supplementation Research Articles

Can adaptation to nitrate supplementation and provision of fermentable energy reduce nitrite accumulation in rumen contents in vitro?

Nitrate (NO3–) supplementation is a promising methane mitigation strategy for ruminants, but can cause nitrite (NO2–) poisoning. Because some nitrite reductases are NADH-dependent, we hypothesised that replacing glucose with glycerol would increase the NADH yield and so enhance nitrite reductase activity and reduce ruminal NO2– accumulation and toxicity risk. We also hypothesised that adapting sheep to dietary NO3– would limit the accumulation of NO2– when NO3– was added to rumen fluid. Changes in NO3– and NO2– catabolism and CH4 production, resulting from supplementation with glycerol to enhance NADH supply, were studied in vitro. In Experiment 1, rumen fluid from sheep adapted to dietary NO3– (2% of DM intake) or urea (1.1% of DM intake) was incubated with NO3– or urea, respectively. Additionally, ground oaten hay was added to incubations alone (control), or with glucose or glycerol. In Experiement 2, sheep were adapted for 9 weeks to dietary NO3– or urea. Nitrate (2% NO3– of substrate DM) was added to incubated digesta from NO3–- or urea-supplemented sheep, while urea (1.1% of substrate DM) was added to digesta from urea-supplemented sheep. In both studies, triplicate incubations were terminated at nine time points up to 24 h. Methane emissions were lower in all NO3– treatments (P < 0.05). Contrary to our hypotheses, both glycerol supplementation (Experiment 1) and prior adaptation to NO3– (Experiment 2) increased NO2– accumulation. In Experiment 1, there was no difference in ruminal NO2– concentration between the unsupplemented control and added glucose treatments. Nitrous oxide accumulated in NO3– treatments only with rumen fluid from sheep adapted to dietary urea (P < 0.05). In summary, NO2– accumulation in vitro was not reduced by adaptation to NO3– or by glucose or glycerol supplementation, disproving the hypotheses regarding the role of NADH availability and of NO2– adaptation in reducing ruminal NO2– accumulation and toxicity risk.

The effect of replacing soya bean oil with glycerol in diets on performance, egg quality and egg fatty acid composition in laying hens

The objective of this experiment was to replace soya bean oil with glycerol in laying hen diets and assess the change’s effect on performance, parameters of egg quality and the egg fatty acid profile. A total of 60 44-week-old Hy-Line W36 laying hens were distributed according to a completely randomised experimental design into four treatments consisting of glycerol substitutions for soya bean oil dietary at varying inclusion levels (0%, 25%, 50% and 75%), with five replicates of three birds each. Dietary treatments had no significant effect on BW change, egg production, feed intake, feed conversion ratio, egg weight and egg mass of laying hens. The inclusion of glycerol in the diet of laying hens had no significant effect on egg specific gravity, eggshell breaking strength, eggshell weight, eggshell thickness, egg shape index, albumen index, yolk index, haugh unit, albumen pH, yolk pH and egg yolk colour values. The inclusion of glycerol in the diet of laying hens had no significant effect on palmitic, palmitoleic, stearic, oleic and linolenic acid contents of the egg yolk. The linoleic acid and polyunsaturated fatty acid contents of the egg yolk significantly decreased with the higher levels of dietary glycerol supplementation (P<0.05). The results of this study show that it is possible to replace 75% of soya bean oil (4.5% in diet) with glycerol.

Effects of feeding dry glycerol on milk production, nutrients digestibility and blood components in primiparous Holstein dairy cows during the early postpartum period

The aim of this study was to evaluate the glucogenic property of glycerol supplementation in the dairy cow’s diet. Sixty primiparous cows (control, n=30, and glycerol supplemented, n=30) were used to measure milk yield and components, blood hormone and metabolite profiles, and body condition score. Feed intake and apparent total-tract digestibility were also measured using 10 primiparous cows (control, n=5, and glycerol supplemented, n=5). Dry glycerol was top dressed at 250 g/day/cow from parturition to 21 days postpartum. Average feed intake, milk yield and components were not affected by glycerol supplementation. Apparent total–tract digestibility of organic matter and neutral detergent fibre were not influenced by dry glycerol supplementation, but lipid digestibility was greater (p=0.01) in cows fed glycerol. The serum concentration of glucose and insulin tended to be higher in dry glycerol-supplemented cows (p=0.1; p=0.06, respectively). While, serum concentrations of nonesterified fatty acids and β-hydroxybutyrate were not affected. Supplemented cows had lower body condition loss during weeks 1 to 5 after calving (p=0.09). The glucogenic effect of glycerol did not affect milk yield during the first 3 weeks of lactation. However, daily milk yield during the 13 weeks recording period was higher in the glycerol-supplemented cows (28.5 vs. 30.3 kg, p&lt;0.001). Percentages of cows cycling at the planned breeding date was greater (p=0.01) for cows fed dry glycerol. The results demonstrated that feeding dry glycerol as a glucogenic supply could be useful in saving body reserves and improving energy balance of primiparous Holstein dairy cows during the early postpartum period.

Biochemical conversion of sugarcane straw hemicellulosic hydrolyzate supplemented with co-substrates for xylitol production

Biotechnological production of xylitol is an attractive route to add value to a sugarcane biorefinery, through utilization of the hemicellulosic fraction of sugarcane straw, whose availability is increasing in Brazil. Herein, supplementation of the sugarcane straw hemicellulosic hydrolyzate (xylose 57gL−1) with maltose, sucrose, cellobiose or glycerol was proposed, and their effect as co-substrates on xylitol production by Candida guilliermondii FTI 20037 was studied. Sucrose (10gL−1) and glycerol (0.7gL−1) supplementation led to significant increase of 8.88% and 6.86% on xylose uptake rate (1.11gL−1h−1 and 1.09gL−1), respectively, but only with sucrose, significant increments of 12.88% and 8.69% on final xylitol concentration (36.11gL−1) and volumetric productivity (0.75gL−1h−1), respectively, were achieved. Based on these results, utilization of complex sources of sucrose, derived from agro-industries, as nutritional supplementation for xylitol production can be proposed as a strategy for improving the yeast performance and reducing the cost of this bioprocess by replacing more expensive nutrients.

Glicerina de baixa pureza na suplementação de bovinos terminados a pasto: análise bioeconômica

This study aimed to evaluate the dry matter intake, digestibility of diet components, performance, feed conversion, carcass characteristics and economics aspects of inclusion with low purity glycerin supplementation on cattle finished on pasture with Brachiaria decumbens. We used 35 male cattle bulls, predominantly Nellore, with initial body weight of 428.0 ± 32.11 kg, distributed in a completely randomized design with five treatments and seven replications. Treatments consisted of glycerin inclusion levels (0, 3, 6, 9 and 12%) in the dry matter (DM). The animals were weighed every 28 days to assess the weight gain (ADG) and adjust the diet. At the end of the experiment the animals were weighed to obtain the average final body weight (BWF) and slaughtered to evaluate the carcass yield (HCY) and carcass traits. The economic analysis was conducted in relation to weight gain in kilos, in order to verify the feasibility of the use of diets with five levels of glycerin, without considering other fixed and operational costs. Increased linearly (P <0.05) levels of glycerin on the intake and digestibility of ether extract and ADG. Linear effect (P <0.05) on the digestibility of neutral detergent fiber (CDFDN), crude protein (CDCP) and feed conversion (FC). No effects were observed (P <0.05) the inclusion of glycerin on carcass traits evaluated. The inclusion of glycerin reduced the cost of production of meat at sign when the price of this ingredient represented up to 70% of the price of corn. Glycerin low purity can be included in the diet of cattle uncastrated finishing the pasture with improved performance and ncreased economic benefits.

Melatonin Effect on Immature Mouse Testicular Tissues, Vitrified-Thawed With Different Cryoprotectant Media

Background: Freezing of the immature testis tissue and then its transplantation can be considered a major step in fertility preservation for young boys with cancer. Objectives: The objective of this study was to investigate the antioxidant effects of melatonin on histological structure of seminiferous tubules that were vitrified-thawed with different cryoprotectant media. Materials and Methods: Male mice were randomly assigned to one of 10 experimental groups. Testes of 6-day-old BALB/c male mice pups were extracted and vitrified-thawed with different vitrification media with melatonin and without melatonin. Then, their testes were stained with haematoxylin-eosin. Results: The result showed that supplementation of glycerol based media with melatonin has reduced injury to histological structure of seminiferous tubules in the 6-day-old male BALB/c mice pups testes (P = 0.004). Conclusions: It seem that melatonin due to its antioxidant properties, if added to glycerol based media, reduces the harmful effects of freezing-thawing process, and protects seminiferous tubules histological structure from oxidative injury.

The Effects of Hyperhydrating Supplements Containing Creatine and Glucose on Plasma Lipids and Insulin Sensitivity in Endurance-Trained Athletes.

The addition of carbohydrate (CHO) in the form of simple sugars to creatine (Cr) supplements is central. The study aimed to determine whether ingestion of glucose (Glu) simultaneously with Cr and glycerol (Cr/Gly) supplement is detrimental to plasma lipids of endurance-trained individuals and find out whether modification arising can be attenuated by replacing part of the Glu with alpha lipoic acid (Ala). Twenty-two endurance-trained cyclists were randomized to receive Cr/Gly/Glu (11.4 g Cr-H2O, 1 g Gly/kg BM, and 150 g Glu) or Cr/Gly/Glu/Ala (11.4 g Cr-H2O, 1 g Gly/kg BM, 100 g Glu, and 1 g Ala) for 7 days. Fasting concentration of TAG increased significantly (P < 0.01) after supplementation with Cr/Gly/Glu (before: 0.9 ± 0.2 mmol/L; after: 1.3 ± 0.4 mmol/L) and Cr/Gly/Glu/Ala (before: 0.8 ± 0.2 mmol/L; after: 1.2 ± 0.5 mmol/L) but changes were not different between the groups. Supplementation significantly (P < 0.05) increased the TAG to HDL-cholesterol ratio but had no effect on fasting concentration of total, HDL-, and LDL-cholesterol and insulin resistance. Thus, addition of Glu to Cr containing supplements enhances plasma TAG concentration and the TAG to HDL-cholesterol ratio and this enhancement cannot be attenuated by partial replacement of Glu with Ala.

English

The effects of overrun and glycerol as a cryoprotectant on viability of probiotics in frozen yogurt were investigated. Frozen yogurt was prepared with different types of probiotics (Lactobacillus acidophilus and Bifidobacterium lactis) along with normal yogurt starter culture (Streptococcus salivarius ssp. thermophiles and L. delbrueckii ssp. bulgaricus). Frozen yogurt mixture was supplemented with 1.5, 3 and 4.5% glycerol and was frozen with 60, 80 and 100% overrun. Viability of probiotic bacteria after freezing and during storage period of 12 weeks was investigated. Supplementation of glycerol in the mixture has improved the survival of L. acidophilus and B. lactis during the frozen storage. At the end of storage period the overall loss in viability of the L. acidophilus with 60, 80 and 100% overrun was 1.81, 1.96 and 2.24 log CFU/g, respectively. The B. lactis viability loss with 60, 80 and 100% overrun was 2.11, 2.26 and 2.26 log CFU/g, respectively. All the supplemented probiotics maintained the minimum concentration of 10 7 CFU/g in frozen yogurt during frozen storage, which is required for beneficial health effects in the host. © 2015 Friends Science Publishers

Enhanced production of nargenicin A(1) and generation of novel glycosylated derivatives.

Nargenicin A1, an antibacterial polyketide macrolide produced by Nocardia sp. CS682, was enhanced by increasing the pool of precursors using different sources. Furthermore, by using engineered strain Nocardia sp. ACC18 and supplementation of glucose and glycerol, enhancement was ~7.1 fold in comparison to Nocardia sp. CS682 without supplementation of any precursors. The overproduced compound was validated by mass spectrometry and nuclear magnetic resonance analyses. The novel glycosylated derivatives of purified nargenicin A1 were generated by efficient one-pot reaction systems in which the syntheses of uridine diphosphate (UDP)-α-D-glucose and UDP-α-D-2-deoxyglucose were modified and combined with glycosyltransferase (GT) from Bacillus licheniformis. Nargenicin A1 11-O-β- D-glucopyranoside, nargenicin A1 18-O-β-D-glucopyranoside, nargenicin A111 18-O-β-D- diglucopyranoside, and nargenicin 11-O-β-D-2-deoxyglucopyranoside were generated. Nargenicin A1 11-O-β-D-glucopyranoside was structurally elucidated by ultra-high performance liquid chromatography-photodiode array (UPLC-PDA) conjugated with high-resolution quantitative time-of-flight-electrospray ionization mass spectroscopy (HR-QTOF ESI-MS/MS), supported by one- and two-dimensional nuclear magnetic resonance studies, whereas other nargenicin A1 glycosides were characterized by UPLC-PDA and HR-QTOF ESI-MS/MS analyses. The overall conversion studies indicated that the one-pot synthesis system is a highly efficient strategy for production of glycosylated derivatives of compounds like macrolides as well. Furthermore, assessment of solubility indicated that there was enhanced solubility in the case of glycoside, although a substantial increase in activity was not observed.

Biofuel co-products as swine feed ingredients: Combining corn distillers dried grains with solubles (DDGS) and crude glycerin

The objective of this study was to examine the effects of combining corn DDGS with crude glycerin on growth performance and carcass traits to determine if a high level of crude glycerin supplementation could counteract the impact of corn DDGS on fatty acid profile of pork adipose. The experimental design was a 3×2 factorial arrangement of treatments with three levels of corn DDGS (0, 150, or 250g/kg diet) and two levels of crude glycerin (0 or 100g/kg diet). Pigs were fed one of six experimental diets over a 3-phase feeding program for 84d with each diet within phase formulated to be equal in metabolizable energy (ME) and standardized ileal digestible lysine (SID Lys). Pigs and feeders were weighed every 14d to determine average daily gain (ADG), average daily feed intake (ADFI) and feed efficiency (G:F). On d-84, pigs were weighed and scanned using real-time ultrasound to obtain fat depth and longissimus dorsi muscle (LM) area. Pigs were then harvested at a commercial abattoir and a sample of adipose was collected from the jowl of each pig. Because there was no interaction between level of corn DDGS and crude glycerin fed, only main effects are presented. Pig performance and carcass characteristics were not affected by dietary treatment (P≥0.05). Differences in fatty acid composition were present due to dietary treatment. Increasing the level of corn DDGS reduced concentration of both saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) and increased the concentration of polyunsaturated fatty acids (PUFA) in pork jowl adipose (P<0.01). Pigs fed 100g crude glycerin/kg diet had higher concentrations of MUFA and lower concentrations of PUFA (P<0.05). Diets containing up to 250g corn DDGS/kg and 100g crude glycerin/kg support growth of finishing pigs. However, increasing dietary levels of corn DDGS increased the concentration of unsaturated fatty acids in pork jowl adipose and this was not ameliorated by feeding 100g/kg crude glycerin.

A Method to Utilize Waste Nutrient Sources in Aqueous Extracts for Enhancement of Biomass and Lipid Content in Potential Green Algal Species for Biodiesel Production

In the present study, ten waste nutrient sources namely potato peels, banana peels, cow dung, press mud, molasses, bagasse hydrolysate, glycerol, succinate, cheese whey and cyanobacterial spent media extract were used for the growth of five potential green algal species namely C. reinhardtii, S. obliquus, C. vulgaris, C. minutissima and B. braunii. The nutrient extracts were prepared so as to not interfere with algal biomass harvesting. The effect of waste nutrients was investigated especially on the biomass and lipid accumulation in algae. The lipids so produced were quantified gravimetrically and analyzed using GC-MS and proton NMR. As a result, all the microalgal species showed enhancement in their growth and lipid production with most of the waste nutrients. C. reinhardtii showed maximum increase in lipid production with potato peels (89%) and banana peels (90%). However, a maximum of 130% increase in biomass content was observed in C. vulgaris with glycerol supplementation. 1H-NMR and GC-MS studies showed that carbon supplementation leads to reduction in the aromaticity of lipids and increase in the C16 and C18 fatty acids fractions, respectively rendering it more suitable for biodiesel production.

Effect of dietary glycerin supplementation in the starter diet on broiler performance

This study was conducted to evaluate the performance, carcass composition, and litter moisture of broiler chicks fed crude glycerin for 1&amp;ndash;21 days. The study used 1056 male birds distributed in a completely randomized design, with six treatments (0, 3, 6, 9, 12, and 15% crude glycerin from 1 to 10 days), with eight replicates. After the 10&lt;sup&gt;th&lt;/sup&gt; day, each treatment group was divided into two groups out of which one continued to receive the same glycerin level and the second group started to receive a glycerin-free diet. The parameters weight gain, feed intake, feed : gain, and livability during the first 10 days exhibited a quadratic response (P &amp;lt; 0.05), which predicted higher values at crude glycerin levels of 9.01, 9.02, 9.03, and 6.43%, respectively. From day 1 to day 21, the group receiving crude glycerin throughout the experiment showed a quadratic effect (P &amp;lt; 0.05) for weight gain, feed intake, feed : gain, and livability, with higher values at crude glycerin levels of 6.06, 7.97, 13.11, and 7.69%. As glycerin levels increased, the litter moisture increased linearly (P &amp;lt; 0.05) for both periods. The protein and fat deposition rates and dry matter of the carcasses were not affected (P &amp;gt; 0.05). Considering the period from day 1 to day 21, inclusion of up to 6.06% crude glycerin in the diet provided the best weight gain without affecting the birds&amp;rsquo; performance, the rate of protein and fat deposition on the carcass, or litter moisture compared with birds fed a glycerin-free diet. &amp;nbsp;

Potential of biogas production from swine manure supplemented with glycerine waste

In this study, was studied the biogas generation from swine manure, using residual glycerine supplementation. The biogas production by digestion occurred in the anaerobic batch system under mesophilic conditions (35°C), with a hydraulic retention time of 48 days. The experiment was performed with 48 samples divided into four groups, from these, one was kept as a control (without glycerin) and the other three groups were respectively supplemented with residual glycerine in the percentage of 3%, 6% and 9% of the total volume of the samples. The volume of biogas was controlled by an automated system for reading in laboratory scale and the quality of the biogas (CH4) measured from a specific sensor. The results showed that the residual glycerine has high potential for biogas production, with increases of 124.95%, 156.98% and 197.83% in the groups 3%, 6% and 9%, respectively, relative to the sample control. However, very high organic loads can compromise the process of digestion affecting the quality of the biogas generated in relation to methane.

Glycerol supplementation enhances the protective effect of dietary FloraMax-B11 against Salmonella Enteritidis colonization in neonate broiler chickens

Two independent trials were conducted in the present study to evaluate the effect of 5% glycerol supplementation combined with dietary FloraMax-B11 (FM) against Salmonella Enteritidis colonization in neonate broiler chickens. In each trial, 60 chicks were randomly assigned into 4 groups. Group 1 received a control diet. Group 2 received a control diet supplemented with 5% glycerol. Group 3 received a control diet supplemented with FM, and group 4 received a control diet supplemented with 5% glycerol and FM. At placement, chickens were challenged with Salmonella Enteritidis at 104 cfu/bird. In each trial, 12 chicks were humanely killed 72 h postchallenge, respectively, for Salmonella Enteritidis colonization. Supplementation of 5% glycerol or FM by themselves, showed no significant effect on Salmonella Enteritidis recovery or incidence when compared with control nontreated chickens in both trials. However, no detectable Salmonella Enteritidis was observed in the chickens that received the supplementation of 5% glycerol combined with FM in both trials. Further studies are in progress in older birds to substantiate these findings.

Ingestive behavior of grazing heifers receiving crude glycerin supplementation during the dry rainy season transition

The search to find food alternatives for corn and feeding alternatives that reduce the cost of production has been constant. The use of oleaginous grains to produce ethanol and biodiesel has produced an excess of byproducts, especially biodiesel which produces crude glycerin. The objective of this study was to evaluate the effect of including crude glycerin on the ingestive behavior of crossbred heifers supplemented with pasture. Thirty-six crossbred heifers with an initial mean weight of 301.5 ± 31 kg were distributed in a completely randomized design with four treatments and nine replicates per treatment. The animals were kept in a Brachiaria brizantha (Hochst. ex A. Rich.) Stapf 'Marandu' pasture in a rotational-grazing system. The treatments tested were 0.0%, 3.33%, 6.66%, and 9.99% crude glycerin included in total DM to replace corn (Tea mays L.) Including crude glycerin reduced the time for grazing and eating at the trough and increased idle time. Rumination was quadratically influenced. Eating time (min kg-1 DM and neutral detergent fiber [NDF]) was reduced, while rumination time (min kg-1 DM and NDF) was quadratically affected by adding glycerin. The variables, time spent per ruminated bolus and the number of chews per day, were not affected. The number of boluses per day showed a quadratic effect. The number of grazing, idle, ruminating, and eating at the trough periods were not affected by including crude glycerin; means were 15.1, 24.9, and 13.3 and 3.71 periods d-1, respectively. Feed and rumination efficiency (kg h-1 DM and NDF) increased when crude glycerin was included in the diet. Including crude glycerin promotes feed and rumination efficiency in grazing heifers.

Metabolic effects of glycerol supplementation and aerobic physical training on Wistar rats.

We evaluated the effects of oral glycerol supplementation on trained rats fed a normal diet. Wistar rats were distributed among 6 groups in a completely randomized 2 × 3 factorial design. The animals were subjected to 6 weeks of aerobic training. In the last 4 weeks, the animals' diet was supplemented with saline, glucose, or glycerol. Data were subjected to one-way analysis of variance (ANOVA) followed by a Student-Newmann-Keuls test, with values for P < 0.05 considered statistically significant. The change in body mass was lower in the trained groups, and their food and water consumption were higher. Glycerol supplementation resulted in an increase in the levels of triacylglycerol (TAG) and total cholesterol, as well as in the area and diameter of adipocytes. When associated with training, these parameters were similar to those of other trained groups. Levels of low-density lipoprotein + very-low-density lipoprotein cholesterol decreased in the trained animals that received glycerol compared with the non-trained ones. Glycerol consumption caused a reduction in food intake and increased the villous:crypt (V:C) ratio. No changes in glycemia, high density lipoproteins, or density of adipocytes were observed. Supplementation with glycerol together with aerobic physical training promoted beneficial metabolic effects. However, in non-trained rats glycerol increased the diameter and area of adipocytes, as well as the levels of TAG and total cholesterol.

Metabolic parameters in rats receiving different levels of oral glycerol supplementation

The use of glycerol in the diets for animals is of interest because it is a residue of biodiesel production and rich in energy. Thus, this study aimed to evaluate metabolic and physiological parameters of rats receiving supplemental pure glycerol by gavage. We used 30 Wistar rats (initial weight 202.7±29.98g) receiving 0 (control/saline), 200, 400, 800 and 1600mg glycerol/kg of body weight (bidistilled glycerine, 99.85% glycerol) beside food and water ad libitum for 28days. We used a completely randomised design with five treatments and six replicates. At the end of the experiment, the animals were killed, and the results showed that there was no change (p>0.05) in the intake and excretion of water, the average daily weight gain, dry matter, ash and crude protein in the carcass or plasma triacylglycerols. There was a beneficial effect (p<0.05) up to a dose of 800mg/kg glycerol on feed intake, percentage of carcass fat, plasma levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), high-density lipoprotein (HDLc) and low-/very low-density lipoprotein (LDLc+VLDLc). The levels of total cholesterol and glucose were increased with up to a dose of 800mg/kg glycerol (but remained within the normal range); they were reduced with the dose of 1600mg/kg. The total leucocyte count tended to be reduced, although it was within the reference values for rats. There were no renal or pancreatic lesions. In conclusion, glycerol presented as a safe supplement at the studied doses, even having some beneficial effects in a dose-dependent manner in rats.

Crude glycerine inclusion in Limousin bull diets: Animal performance, carcass characteristics and meat quality

Three hundred and six Limousin young bulls (7±1months of age, initial body weight 273±43kg) were used to evaluate the effect of crude glycerine supplementation on animal performance, carcass characteristics and meat quality. Animals were assigned to three different diets: Control (0% of crude glycerine), G2 and G4 (2 and 4% of crude glycerine, respectively). The diets were administrated ad libitum for 240days (final body weight 644±24kg). Average daily weight gain, average daily feed intake, the gain:feed ratio, ultrasound measures in vivo, carcass characteristics, pH, water holding capacity, drip losses, and cooking losses were not affected (P>0.05) by diets. Diet decreased C16:0 (P<0.01) and C16:1 (P<0.05) contents in meat. The G4 meat showed lower C12:0, C14:0, C17:0, C18:0, C18:1, C18:2, C18:3, c9,t11-c18:2, C20:0 and C20:4 levels (P<0.05) than control. Glycerine increased desirable fatty acid percentages (P<0.05) in intramuscular fat.

Cultivation of the fresh water microalga Chlorococcum sp. RAP13 in sea water for producing oil suitable for biodiesel

Chlorococcum sp. RAP13—a fresh water microalga was evaluated for growth and lipid production in medium containing 50 % natural sea water under both phototrophic and heterotrophic cultivation modes. The algal cells adapted very well to the sea water and accumulated up to 38 % of their dry cell weight as lipids under heterotrophic cultivation. Biomass production and lipid accumulation were significantly higher than those in fresh water. Supplementation of biodiesel industry waste glycerol in sea water resulted in the highest yield of oil (330 mg L−1), and the biomass yield was 0.85 g L−1. The composition of oil produced under phototrophic and heterotrophic growth was significantly different, with the former enriched in polyunsaturated fatty acids while the latter contained more of medium chain saturated fatty acids and monounsaturated fatty acids suitable for biodiesel production. While the use of sea water reduces the requirement of mineral supplementation and saves fresh water, the ability to form oil from waste glycerol indicates the potential to recycle this waste. To the best of our knowledge, this is the first report on cultivation of the fresh water alga Chlorococcum sp. under heterotrophic mode in sea water.

Glycerol supplementation of the growth medium enhances in situ detoxification of furfural by Clostridium beijerinckii during butanol fermentation

Lignocellulose-derived microbial inhibitors such as furfural and 5-hydroxymethyl furfural adversely affect fermentation of lignocellulosic biomass hydrolysates to fuels and chemicals due to their toxicity on fermenting microbes. To harness the potential of lignocellulose as a cheap source of fermentable sugars, in situ detoxification of furfural and other lignocellulose-derived microbial inhibitors is essential. To enhance in situ detoxification and tolerance of furfural by Clostridium beijerinckii NCIMB 8052 during acetone-butanol-ethanol (ABE) fermentation, the effect of glycerol on NADH/NADPH generation and ABE production by furfural (4, 5, and 6 g/L)-challenged cultures was investigated in this study. In all instances, beneficial outcomes were observed. For example, the fermentation medium supplemented with glycerol and subjected to 5 g/L furfural elicited up to 1.8- and 3-fold increases, respectively, in NADH and NADPH levels in C. beijerinckii 8052 relative to the control culture. These critical changes are the likely underpinnings for the glycerol-mediated 2.3-fold increase in the rate of detoxification of 5 g/L furfural, substrate consumption, and ABE production compared to the unsupplemented medium. Collectively, these results demonstrate that increased intracellular NADH/NADPH in C. beijerinckii 8052 due to glycerol utilization engenders favorable effects on many aspects of cellular metabolism, including enhanced furfural reduction and increased ABE production.