Source Of Fermentable Carbohydrate Research Articles

Optimization of lactic acid production from apple and tomato pomaces by thermotolerant bacteria

The production of lactic acid (LA) through biomass fermentation represents a promising alternative to the chemical synthesis. The use of agri-food by-products as fermentable carbohydrate sources can improve process sustainability by reducing waste and valorizing residual biomass. This study assessed the use of apple and tomato pomaces for producing LA through fermentation using thermotolerant bacteria under aerobic and non-sterile conditions. Three bacteria were evaluated and Heyndrickxia coagulans DSM 2314 was selected for its ability to produce LA from hydrolyzates of apple pomace (APH) and tomato pomace (TPH). The fermentation conditions were optimized to maximize LA production from APH, TPH and a mixture of both hydrolyzates. Therefore, LA productions ranged from 36.98 ± 0.41 to 40.72 ± 0.43 g/L, with yields from 0.86 ± 0.02 to 1.01 ± 0.01 g/g. Yeast extract was necessary as a nitrogen source for fermenting APH, while TPH and the mixture of both hydrolyzates did not require any supplementation. Other nitrogen sources, such as wine lees, urea and NH3Cl, were tested for fermenting APH. However, mixing this hydrolyzate with TPH proved to be the most viable alternative. This study demonstrates the potential for valorizing apple and tomato pomaces into LA under feasible fermentation conditions.

Life cycle assessment of fermentative production of lactic acid from bread waste based on process modelling using pinch technology

Bread waste (BW), a rich source of fermentable carbohydrates, has the potential to be a sustainable feedstock for the production of lactic acid (LA). In our previous work, the LA concentration of 155.4 g/L was achieved from BW via enzymatic hydrolysis, which was followed by a techno-economic analysis of the bioprocess. This work evaluates the relative environmental performance of two scenarios - neutral and low pH fermentation processes for polymer-grade LA production from BW using a cradle-to-gate life cycle assessment (LCA). The LCA was based on an industrial-scale biorefinery process handling 100 metric tons BW per day modelled using Aspen Plus. The LCA results depicted that wastewater from anaerobic digestion (AD) (42.3–51 %) and cooling water utility (34.6–39.5 %), majorly from esterification, were the critical environmental hotspots for LA production. Low pH fermentation yielded the best results compared to neutral pH fermentation, with 11.4–11.5 % reduction in the overall environmental footprint. Moreover, process integration by pinch technology, which enhanced thermal efficiency and heat recovery within the process, led to a further reduction in the impacts by 7.2–7.34 %. Scenario and sensitivity analyses depicted that substituting ultrapure water with completely softened water and sustainable management of AD wastewater could further improve the environmental performance of the processes.

Determination of the Effects of Grape Pomace Addition to Sorghum Sudan Grass on Silage Quality

The aim of this study was to determine the silage quality and in situ degradability of silages prepared with addition of grape pomace into variety of sorghum-sudan grass as rapid fermentable carbohydrate source. Grape pomace obtained at the region was ensiled with sorghum- sudan grass grown at Keskin Fodder Plants Production and Processing Facility at same period at the levels of 0, 10, 20 and 40%. Glass jars (1L) were used for ensiling of silages. Four silage samples were prepared for each treatment groups. After 45 days of ensiling, silage samples were opened and pH, organic acid, nutrient contents, and in situ degradation levels were determined. Among silage fermentation parameters, pH and volatile fatty acid concentrations did not differ among silage prepared from different sorghum-sudan grass varieties (P>0.05), grape pomace significantly increased the pH of sorghum-sudan grass silages and decreased lactic acid concentrations of sorghum-sudan grass silages (P<0.05). Nutrient contents, except CP content, significantly differed between sorghum-sudan grass varieties, addition of grape pomace into sorghum-sudan grass significantly alter the nutrient contents of silages (P<0.05). While in situ OM, NDF and ADF degradabilities were similar between sorghum-sudan grass varieties, addition of grape pomace significantly decreased OM degradability in both sorghum-sudan grass varieties (P<0.05). In conclusion, addition of grape pomace into sorghum-sudan grass up to 40% had some negative effects on silage quality, but it was taught that grape pomace can be utilized as alternatve feedstuffs for ruminants by adding sorghum-sudan grass up to 20%.

EFECTO ADITIVO DE ENSILADOS DE POLLINAZA, CERDAZA Y UREA MEZCLADOS CON MELAZA DE CAÑA Y SUBPRODUCTO DE PANADERÍA EN DIETAS PARA CORDEROS

<p><strong>Background: </strong>The use of silages from non-conventional sources of nitrogen and soluble carbohydrates in feeding lambs is controversial in terms of nutrient supply; due to the minimum number of studies reported to date of <em>in vitro</em> evaluations that allow measuring its nutritional value in ruminants. <strong>Objective:</strong> To evaluate the additive effect and fermentation potential of silages plus concentrates in diets for lambs on the <em>in vitro</em> gas production kinetics. <strong>Methodology:</strong> Six diets (silage + concentrate) were evaluated in a factorial arrangement of 3 N sources (dried poultry litter, fresh swine manure, agricultural urea) × 2 carbohydrate sources (sugar cane molasses, bakery by-product). The diets contained: a) silage (400 g/kg DM) and b) concentrates (600 g/kg DM) based on soybean meal, ground corn, wheat bran, corn stover, fish meal, and vitamin and mineral premix. Average gas production data were analyzed with PROC MIXED and the gas production curves were fitted into the Exponential Logistic model with PROC NLMIXED. <strong>Results:</strong> The PO+MC (151.87 mL/gas MS) and CF+MC (153.12 mL/gas MS) treatments had higher average gas production during incubation. An additive effect was observed on the maximum asymptote of gas production in the CF+MC (+ 4.26%) and PO+MC (+ 3.75%) diets (<em>P</em><0.01). Diets based on PO or CF combined with MC and SPP had higher IVDMD, IVOMD, and IVNDFD than the control treatment (UR). <strong>I</strong><strong>mplications: </strong>The inclusion in diets for growing lambs of corn stover silage based on rapidly fermentable carbohydrate sources with non-protein nitrogen from pig and poultry excreta in diets for growing lambs has associative effects on nutrient degradability and its fermentation potential in small ruminant feed. <strong>Conclusions:</strong> The PO+MC treatment has a higher potential for gas production due to the associative effect of its components. </p>

Economic and environmental performance of non-cellulosic fermentable carbohydrates production for biofuels and chemicals

Fermentable carbohydrates (FC) are a major cost component and a major environmental burden in the production of biofuels and bio-based commodity chemicals; consequently, the cost of FC determines the economic feasibility and environmental performance of biofuels and bio-based commodity chemicals. Producing FC with conventional technology and without the additional processing steps of food-grade sugar can result in a low-cost industrial-grade fermentable sugar that is competitive with that of raw sugar. This study assesses the minimum selling prices (MSP) and the life cycle environmental impacts of FC produced from energycane, sweet sorghum, sugar beet, and corn all of which are grown in the US. The study also assesses FC produced from sugarcane grown in Brazil, which is used as a gauging reference of a low-cost FC source. The MSP was determined by calculating the prices of FC that will result in a net present value (NPV) of 0 with a discount rate that is better than that of a low-risk investment. Environmental performance was assessed by accounting for the life cycle emissions of greenhouse gas, use of fossil energy, and eutrophication potential. The MSP of FC produced from the evaluated feedstocks varies from $0.30 kg−1 for FC produced from sugarcane to $0.50 kg−1 for FC produced from sugar beet or sweet sorghum. The study shows that in the US, FC from energycane has a similar MSP of $0.40 kg−1 to that of FC from corn at $0.38 kg−1, but FC from energycane has lower environmental impacts than FC from corn. The potential for economic feasibility exists in the US for FC from energycane, and with similar environmental impacts to sugarcane and lower environmental impacts than corn. Opportunities for a lower MSP of $0.32 kg−1 exist by using sweet sorghum as a supplementary feedstock with energycane to increase the utilization of the processing plant and reduce the capital cost per unit mass of FC. Producing FC in the US from energycane and supplementing it with sweet sorghum results in an MSP that is lower than raw sugar, which varied from $0.20 kg−1 to $0.63 kg−1 and averaged $0.35 kg−1 from years 2005 through 2019. This shows that the US has access to a low-cost source of FC with lower environmental impacts than corn and with a price that is not subjected to external factors like the fluctuating price of raw sugar.

In vitro fermentation of onion cell walls and model polysaccharides using human faecal inoculum: Effects of molecular interactions and cell wall architecture

Plant primary cell walls provide a primary dietary source of fermentable carbohydrates. They are typically based on a cellulose network cross-linked by xyloglucan, with pectin incorporated, but the relative contributions of components and their architectural arrangement to gut fermentation performance is incompletely understood. Onion cell walls (OCW) were isolated and used as a primary cell wall model. OCW, models for their main constituents (xyloglucan, pectin, cellulose) and the physical mixture of these model polysaccharides (Mix) were fermented in vitro up to 48h, using a human faecal inoculum. Each constituent in Mix was fermented to a similar extent as single-component substrates, with comparable gas and short chain fatty acid (SCFAs) production. The microbiota responded differently and specifically to each polysaccharide, with the microbial community for Mix reflecting both pectin and xyloglucan. OCW was degraded more slowly at the early stage of fermentation, with less SCFAs produced compared with Mix, though a more extensive fermentation occurred by the end of fermentation, due to the slow but essentially complete fermentation of cellulose in OCW but not Mix. Microbiota shifts for OCW were different to those for Mix. The architecture of OCW as well as polysaccharide composition determined both fermentation outcomes and microbial community shifts.

Essential oil and apple pomace affect fermentation and aerobic stability of alfalfa silage

This study assessed the effects of the additions of an essential oil (EO), composed of ricinoleic acid, cardol, cardanol, and apple pomace, on fermentation quality and aerobic stability of alfalfa silages. The experimental treatments consisted of T1) alfalfa (control), T2) alfalfa with EO, T3) alfalfa (75%) with apple pomace (25%), T4) alfalfa (75%) with apple pomace (25%) and EO, T5) alfalfa (50%) with apple pomace (50%), T6) alfalfa (50%) with apple pomace (50%) and EO, T7) alfalfa (25%) with apple pomace (75%), and T8) alfalfa (25%) with apple pomace (75%) and EO. The addition of apple pomace decreased the silage pH compared with the control (P <0.01). Apple pomace at 25% level increased the total volatile fatty acid (iVFA) content (P <0.05). Essential oil (EO) decreased tVFA and increased dry matter (DM) content 90 days after ensiling (P <0.01). Apple pomace decreased ammonia (N-NH3), crude protein (CP), and crude ash (CA) content and increased the amounts of neutral detergent fibre (NDF) and acid detergent fibre (ADF) (P <0.01). Essential oil and apple pomace (level 75%) increased effective digestibility (P <0.05). Apple pomace decreased aerobic stability and the addition of EO increased aerobic stability (P <0.05). Thus, use of apple pomace as a source of fermentable carbohydrate and/or the addition of EO in the preparation of high-quality alfalfa silage is recommended to offset its high buffering capacity and low carbohydrate content.

Biochemical conversion of Brassicacarinata biomass to organic acids

AbstractThe economics of the inedible oilseed crop Brassica carinata as a source of renewable fuels can be enhanced by converting its cellulosic biomass to value‐added chemicals, such as organic acids. We investigated the biochemical conversion of carinata biomass to propionic acid by first pretreating the carinata meal (CM), which is obtained after extraction of the oil from carinata seeds, with concentrated phosphoric acid to remove hemicellulose and gain access to the cellulose constituent of the meal. We then subjected the pretreated meal to enzymatic hydrolysis with cellulase enzyme to depolymerize cellulose to glucose. The overall conversion of carinata cellulose to glucose was 85%, which is promising. Finally, the recovered glucose was successfully fermented primarily to propionic acid using the bacterium Propionibacterium freudenreichii with a yield of 0.57 g of produced propionic acid per gram of consumed cellulosic glucose. The biobased propionic acid and other co‐produced organic acids can serve as renewable building blocks for manufacturing industrial chemicals and food preservatives replacing fossil‐derived organic acids. Hence, CM constitutes a renewable source of fermentable carbohydrates potentially improving the economics and sustainability of the carinata value chain.

PSIV-22 The effects of altering ruminal fermentable carbohydrate supply in finishing diets containing distillers grains on rumen fermentation characteristics and nitrogen utilization

Abstract This study examined the effects of altering ruminal fermentable carbohydrate (RFC) supply by feeding different amounts of corn and wheat in finishing cattle diets containing 15% corn dried distillers grains [DDGS; dry matter (DM) basis] on ruminal fermentation characteristics and nitrogen (N) utilization. Six ruminally-cannulated crossbred heifers were used in a replicated 3 × 3 Latin square design with 28 d periods. Dietary treatments were either corn (73% of diet DM; CON), 53:20 corn:wheat blend (20W) or 33:40 corn:wheat blend (40W) as the major fermentable carbohydrate source. Diets were isonitrogenous (12% CP; DM basis). Feed intake was measured daily. Indwelling pH logger were used to measure ruminal pH (d 22 to 28) and ruminal fluid was collected from d 26 to 28 to determine fermentation characteristics, as were feces and urine to measure N excretion. Data was analyzed using PROC MIXED in SAS. Dry matter and N intake tended to be lower (P ≤ 0.07) for heifers fed the 40W compared to the CON and 20W diets. There was no diet effect (P = 0.15) on total VFA concentration; however, the duration and area for pH < 5.5 tended to be longer (P = 0.07) and greater (P = 0.096), respectively, for heifers fed the 20W and 40W compared to the CON diet. There was no diet effect (P ≥ 0.44) on ruminal ammonia concentration and total urine N excretion (g and % of N intake). However, urine urea N (UUN) excretion as a percentage of total urine N tended to be lower (P = 0.05) in heifers fed the 20W and 40W compared to the CON diet. In summary, although altering RFC supply by feeding increasing amounts of wheat resulted in a decrease in UUN excretion, it also caused a decrease in ruminal pH that possibly compromised DM intake.

Effect of supplementation of various fermentable carbohydrate sources in sorghum straw-gliricidia mixed diet on fermentation kinetics measured using in vitro gas production

Supplementation of fermentable carbohydrate in crop by product-based diet is expected to improve the fermentability and reduced methane production. The study evaluated supplementation of various fermentable carbohydrate in sorghum straw-gliricidia mixture basal diet. Sorghum straw-gliricidia mixture was supplemented either with ground corn grain, rice bran or sorghum grain at 10% of DM basal diet. Treatment diets evaluated were: Sorghum + gliricidia leaf meal (Control); Control + 10% ground corn grain (Corn grain); Control + 10% rice bran (Rice bran); Control + 10% sorghum grain (Sorghum). Sorghum straw was chopped and ground then mixed with gliricidia leaf meal at ratio 60:40% DM. The sample was incubated for 48 hours, gas production was recorded at 4, 8,12, 16, 24, 36 and 48 hours. Rumen fluid for medium incubation was collected from sheep fed elephant grass basal diet. Supplementation of rice bran lowered (P<0.05) gas production from insoluble fraction of the diet compared to maize. Rice bran and sorghum decreased gas production at 48 h incubation compared to control (P<0.05). Sorghum supplementation decreased CH4 production. It can be concluded that fermentable carbohydrate supplementation from sorghum grain to sorghum straw-gliricidia mixture reduced percentage of methane production.

A comparison of three highly fermentable carbohydrate sources (corn, cassava powder or cassava pulp) on in vitro digestion

Cassava powder and pulp contain high levels of carbohydrate and variable starch; thus, they have the potential as substitutes for corn grain in cattle rations. This study aims to determine whether cassava (powder and pulp) can replace corn as an energy source in rations. Using a completely randomized design, rations were formulated using three corn, cassava powder or cassava pulp; and palm kernel cake as a protein source with a ratio of 60:40 (carbohydrate:protein source). Cassava powder and cassava pulp in the diet increased (P<0.05) VFA concentration over that from corn (14.6 and 18.2 vs. 11.3mM, respectively) and decreased NH3-N (4.73 and 4.55 vs. 8.26mg/100mL, respectively) in the rumen fluid compared to corn (P<0.05). pH did not change and ranged from 7.10-7.24. Rations containing cassava pulp showed the greatest microbial N concentration (P<0.05) compared to rations containing corn or cassava (5.85 vs. 4.52 and 1.43mg/100mL, respectively). Dry matter digestibility of the ration with cassava powder is higher (P<0.05) than corn and cassava pulp (62.4 vs. 59.4 and 50.6%, respectively). It may be concluded that cassava powder and cassava pulp can substitute corn in ruminant rations with a positive effect on the characteristics of rumen fermentation.

Engineering broad-spectrum digestion of polyuronides from an exolytic polysaccharide lyase.

BackgroundMacroalgae represents a promising source of fermentable carbohydrates for use in the production of energy efficient biofuel. The primary carbohydrate in brown algae is the uronic acid-containing alginate, whereas green algae contains a significant amount of glucuronan. A necessary step in the conversion of these polyuronides to bioethanol is saccharification, which can be achieved by enzymatic or chemical degradation.ResultsPolysaccharide lyases are a class of enzymes which cleave uronic acid-containing glycans via a β-elimination mechanism, acting both endo- and exolytically on their substrates. In the present work, we characterize a putative alginate lyase from Stenotrophomonas maltophilia K279a (Smlt2602) and describe a H208F mutant that, in addition to cleaving alginate-based substrates, displays significant, exolytic glucuronan activity.ConclusionsTo our knowledge this is the first polysaccharide lyase to act exolytically on glucuronan and is an attractive candidate for the broad-spectrum digestion of polyuronides into fermentable monomers.Electronic supplementary materialThe online version of this article (doi:10.1186/s13068-016-0455-8) contains supplementary material, which is available to authorized users.

The effect of palm kernel meal supplementation in the diet on the growth performance and meat quality of swine, and on the level of odorous compounds and bacterial communities in swine manure

In the present study, we aimed to investigate the effect of dietary supplementation of palm kernel meal (PKM), as a fermentable carbohydrate source, on the growth performance, meat quality, concentration of odorous compound, and changes in bacterial community in swine manure. Swine (average initial body weight of 51.36 ± 1.02 kg) were fed diet which included three levels of PKM (0, 2 and 4%), and their manure samples were collected from the slurry pit. Growth performance and meat quality were not affected by PKM treatments (p > 0.05). Levels of phenols and indoles were decreased in the 2 and 4% PKM treatments compared to 0% PKM (control; p < 0.05). Especially, compared to the control, the 2% PKM group showed decreased levels of phenols by 35% and indoles by 34%. Among the dominant bacterial genera, the main change in relative abundance occurred in those belonging to the Firmicutes phylum in PKM treatments. Terrisporobacter and Clostridium were decreased in the PKM groups compared to the control. However, the relative abundance of Intestinibacter, AM406061_g, Coprococcus_g2, Phascolarcotobacterium, EF401875_g, Lactobacillus, and Streptococcus were increased in the PKM group compared to control. Taken together, administration of PKM had a beneficial effect on reducing production of odorous compounds in swine manure, possibly by modulating the communities of predominantly carbohydrateutilizing bacteria in the large intestine of swine.

In Vitro Fermentation of caprine milk oligosaccharides by bifidobacteria isolated from breast-fed infants

This study was conducted to investigate the catabolism and fermentation of caprine milk oligosaccharides (CMO) by selected bifidobacteria isolated from 4 breast-fed infants. Seventeen bifidobacterial isolates consisting of 3 different species (Bifidobacterium breve, Bifidobacterium longum subsp. longum and Bifidobacterium bifidum) were investigated. A CMO-enriched fraction (CMOF) (50% oligosaccharides, 10% galacto-oligosaccharides (GOS), 20% lactose, 10% glucose and 10% galactose) from caprine cheese whey was added to a growth medium as a sole source of fermentable carbohydrate. The inclusion of the CMOF was associated with increased bifidobacterial growth for all strains compared to glucose, lactose, GOS, inulin, oligofructose, 3'-sialyl-lactose and 6'-sialyl-lactose. Only one B. bifidum strain (AGR2166) was able to utilize the sialyl-CMO, 3'-sialyl-lactose and 6'-sialyl-lactose, as carbohydrate sources. The inclusion of CMOF increased the production of acetic and lactic acid (P < 0.001) after 36 h of anaerobic fermentation at 37°C, when compared to other fermentable substrates. Two B. bifidum strains (AGR2166 and AGR2168) utilised CMO, contained in the CMOF, to a greater extent than B. breve or B. longum subsp longum isolates, and this increased CMO utilization was associated with enhanced sialidase activity. CMOF stimulated bifidobacterial growth when compared to other tested fermentable carbohydrates and also increased the consumption of mono- and disaccharides, such as galactose and lactose present in the CMOF. These findings indicate that the dietary consumption of CMO may stimulate the growth and metabolism of intestinal Bifidobacteria spp. including B. bifidum typically found in the large intestine of breast-fed infants.

Feasibility of acetone–butanol–ethanol (ABE) fermentation from Amorphophallus konjac waste by Clostridium acetobutylicum ATCC 824

Using Amorphophallus konjac waste as a source of fermentable carbohydrate, the feasibility of acetone–butanol–ethanol (ABE) fermentation by Clostridium acetobutylicum ATCC 824 was investigated in this study. Two distinct combination strategies for the enzymatic hydrolysis and fermentation, simultaneous saccharification and fermentation (SSF) and separate hydrolysis and fermentation (SHF), for konjac waste fermentation were compared. β-Mannanase was added to facilitate the hydrolysis of glucomannan and to increase the fermentability of the substrate. The ABE concentration (6.64g/L) from SSF was less than that from SHF; the result from the control experiment was 4.34g/L of ABE. SHF obtained a higher production of total ABE solvents (10.95g/L) with 7.10g/L of butanol at a productivity rate of 0.30g/L/h. The effect of the bioactive alkaloid abundant in the konjac waste on ABE fermentation was evaluated. The results indicated that the alkaloid affected the ABE fermentation results when using C. acetobutylicum, and the effective extraction of alkaloids can help to increase the butanol concentration and shorten the fermentation period. Therefore, the utilization of Amorphophallus konjac waste (a low-cost agricultural resource) in ABE fermentation provides an alternative to increase the economic viability of ABE production.

Impact of dietary protein on microbiota composition and activity in the gastrointestinal tract of piglets in relation to gut health: a review

In pigs, the microbial ecosystem of the gastrointestinal tract (GIT) is influenced by various factors; however, variations in diet composition have been identified as one of the most important determinants. Marked changes in fermentation activities and microbial ecology may occur when altering the diet, for example, from milk to solid feed during weaning. In that way, access of pathogens to the disturbed ecosystem is alleviated, leading to infectious diseases and diarrhea. Thus, there is increasing interest in improving intestinal health by use of dietary ingredients suitable to beneficially affect the microbial composition and activity. For example, fermentable carbohydrates have been shown to promote growth of beneficial Lactobacillus species and bifidobacteria, thereby enhancing colonization resistance against potential pathogens or production of short-chain fatty acids, which can be used as energy source for epithelial cells. On the other hand, fermentation of protein results in the production of various potentially toxic products, such as amines and NH3, and is often associated with growth of potential pathogens. In that way, excessive protein intake has been shown to stimulate the growth of potentially pathogenic species such as Clostridium perfringens, and to reduce fecal counts of beneficial bifidobacteria. Therefore, it seems to be a promising approach to support growth and metabolic activity of the beneficial microbiota by developing suitable feeding strategies. For example, a reduction of dietary CP content and, at the same time, dietary supplementation with fermentable carbohydrates have proven to successfully suppress protein fermentation. In addition, the intestinal microbiota seems to be sensible to variations in dietary protein source, such as the use of highly digestible protein sources may reduce growth of protein-fermenting and potentially pathogenic species. The objective of the present review is to assess the impact of dietary protein on microbiota composition and activity in the GIT of piglets. Attention will be given to studies designed to determine the effect of variations in total protein supply, protein source and supplementation of fermentable carbohydrates to the diet on composition and metabolic activity of the intestinal microbiota.

Effect of ensiling moist field bean (Vicia faba), pea (Pisum sativum) and lupine (Lupinus spp.) grains on the contents of alkaloids, oligosaccharides and tannins.

Ensiling legume grain may be an inexpensive and ecologically interesting method to produce a high-protein feed of local origin. The typically patchy maturation recommends harvesting and ensiling the seeds in moist condition. Developing a method for preserving legume grains harvested before maturation by lactic acid fermentation would have several advantages. Under laboratory conditions, crushed legume seeds of beans, peas and lupines with high moisture content of 35% were ensiled with different additives (molasses and lactic acid bacteria). To characterize the final silages, contents of proximate nutrients and antinutritional factors (alkaloids, oligosaccharides, tannins) were analysed. The addition of lactic acid bacteria ensured a fast and pronounced lactic acid production and decreased contents of undesired fermentation products like ethanol. An additional use of molasses for ensilage did not provide a remarkable additional benefit. Excluding sugar and starch, the contents of proximate nutrients were not remarkably altered after ensiling. As an overall effect, lactic acid fermentation reduced tannins and oligosaccharides. It can be supposed that the oligosaccharides after breakdown of the complex molecules acted as a source of fermentable carbohydrates. A relevant reduction of alkaloids did not occur. The lactic acid fermentation of legume grains can be recommended as an appropriate method for conservation. With respect to the economic advantages and compared with methods of chemical preservation, the lactic acid fermentation of legume grains under anaerobic conditions is an environmentally compliant procedure and therefore also an option for organic farming.

BACTERIAL PRESERVATION OF PINK SALMON USING POTATOES AS A CARBOHYDRATE SOURCE

Salmon processing waste can create disposal issues unless a fish meal plant is located nearby. Other preservation methods, such as fermentation with lactic acid bacteria (LAB), are less energy intensive, but require an added carbohydrate. In this study, pink salmon heads (raw, smoked or cooked) were mixed with potatoes at different ratios and incubated with LAB. An initial pH drop was observed, with concurrent production of lactic acid, for all salmon–potato silages within 24 h; however, only silages composed of 100% potato or salmon with added sucrose became stable and remained at or below pH 4.8 for 60 days. Increasing the potato content of the potato–salmon silage increased the initial acidification, but did not prevent a rise in pH during storage. This study suggests that discarded agricultural products such as potatoes might be useful as a carbohydrate supplement for LAB preservation of fish by-products. PRACTICAL APPLICATIONS Pink salmon by-products, such as heads and viscera, create disposal issues for fish processors in Alaska. However, preserving these high-protein wastes through natural acidification (using lactic acid bacteria) requires an added carbohydrate to promote fermentation during silage production. Agricultural waste products such as discarded potatoes represent a convenient source of fermentable carbohydrate. Once preserved, fish processing waste offers an inexpensive feed source for agricultural animals, or as aquaculture feeds or local compost for vegetable farming.

The influence of growth conditions on enterocin-like production by Enterococcus faecium CWBI-B1430 and Enterococcus mundtii CWBI-B1431 isolates from artisanal Peruvian cheeses

Strains of Enterococcus faecium CWBI-B1430 and Enterococcus mundtii CWBI-B1431, isolated from artisanal-produced Peruvian cheeses, offer a broad potential application as food biopreservatives for heat-processing treatments. The aim of this work was to optimize the production conditions and medium composition for the production of bacteriocin-like substances (BLIS). The kinetics of the BLIS production for both strains is a growth-associated process, and the maximum inhibitory activity for E. faecium CWBI-B1430 and E. mundtii CWBI-B1431 was achieved after 9 and 8 h of fermentation, respectively. Temperature, initial pH, oxygen level, and their interactions all influence BLIS production for both strains; this influence was specific for each strain. The bacteriocin gene expression in a 20.0-L fermentor confirms previous work carried out by fermentation in the flask; the first reports of expression revealed mundticin KS from E. faecium and enterocin P from E. mundtii. Both strains demonstrated antilisteria activity and were multi-producers of enterocin. Furthermore, the study with whey milk as an inexpensive source of fermentable carbohydrates indicated lower BLIS production than that obtained with M17LG broth. The short chain fatty acid (SCFA) analyses offer a new alternative use for both strains, as strains probiotic, for propionic acid production.

In Vitro Digestion and Fermentation Characteristics of Temulose Molasses, a Coproduct of Fiberboard Production, and Select Temulose Fractions Using Canine Fecal Inoculum

It is of interest to discover new fermentable carbohydrate sources that function as prebiotics. This study evaluated the hydrolytic digestibility, fermentative capacity, and microbiota modulating properties of Temulose molasses, four hydrolyzed fractions of Temulose molasses, short-chain fructooligosaccharides (scFOS), and a yeast cell wall preparation (Safmannan). These substrates resisted in vitro hydrolytic digestion. Each substrate was fermented in vitro using dog fecal inoculum, and fermentation characteristics were quantified at 0 and 12 h. All Temulose molasses substrates decreased pH by at least 0.64 unit and resulted in greater (P < 0.05) butyrate and total short-chain fatty acid (SCFA) production compared to scFOS and Safmannan. Temulose molasses substrates resulted in higher (P < 0.01) or equal Bifidobacterium spp. concentrations compared to scFOS. Temulose molasses substrate and its fractions demonstrated prebiotic characteristics as indicated by low hydrolytic digestibility, high fermentability, and enhanced growth of microbiota considered to be beneficial to health.