Anaerobic Yeast Research Articles

Развитие микобиоты ягод крыжовника при хранении

Berries are a source of biologically active substances in human diet. Gooseberries have attractive sensory properties and high nutritional value. However, modern science knows little about micromycetic contamination of gooseberry. The research objective was to define the mycobiota composition of Ribes uva-crispa L. varieties during storage. The study featured the mycobiota of gooseberry varieties Senator and Rozoviy 2. The berries were harvested on the test field of the Siberian Federal Scientific Center of Agro-BioTechnologies of the Russian Academy of Sciences. They were stored for 18 days at 18 ± 2 and 4 ± 2°C and a relative humidity of 90–95%. The authors used standard research methods to identify the mycobiota and attribute them to nine genera by morphological structure: Aspergillus, Mucor, Penicillium, Rhizopus, Alternaria, Aureobasidium, Cladosporium, Cryptococcus, and anaerobic yeast. The frequency of occurrence varied from 20 to 100%. Micromycetes of the genus Fusarium were present only in the Senator sample, which also demonstrated a 100% occurrence of Penicillium, Alternaria, Aspergillus, and Cladosporium. In the sample of Rozoviy 2, Penicillium and Cladosporium occurred in 80%. The Senator sample was twice as low in micromycetes as the Rozoviy 2 berries: 558 vs. 945, respectively. The Senator berries grew in micromycetes due to the Cladosporium fungi while Rozoviy 2 owed its micromycetic increase to Penicillium. Both varieties showed no signs of ascomycetes known as a powdery mildew agent. During storage, the growth of yeast and yeast-like fungi depended on the variety of berries while the growth of mycelial fungi depended on the variety and storage temperature. The data obtained expand the scope of scientific knowledge about the generic composition of gooseberry mycobiota, which may help to select correct anti-spoilage measures.

Caproicibacterium argilliputei sp. nov., a novel caproic acid producing anaerobic bacterium isolated from pit clay.

An anaerobic, Gram-positive, rod-shaped, motile and spore-forming bacterium, designated strain ZCY20-5T, was isolated from pit clay of Chinese strong-aroma type Baijiu (Chinese liquor). Phylogenetic analyses based on 16S rRNA gene and genome sequences showed that strain ZCY20-5T belonged to the genus Caproicibacterium, family Oscillospiracheae, but it showed low similarity to the type species Caproicibacterium amylolyticum LBM18003T (98.00 %) and Caproicibacterium lactatifermentans LBM19010T (95.67 %). In anaerobic yeast extract medium, growth was observed at 20-45 °C (optimum, 35-40 °C), at pH 4.0-9.0 (optimum, pH 6.5-7.0) and with 0.0-2.0 % NaCl (w/v). The predominant fatty acids were C16 : 0, C14 : 0, C13 3-OH and C16 3-OH, and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, three phospholipids of unknown structure containing glucosamine and two unidentified phospholipids. Strain ZCY20-5T exhibited an 81.32 % pairwise average nucleotide identity value, a 78.98 % average amino acid identity value and a 22.30 % digital DNA-DNA hybridization value compared to its closest relative C. amylolyticum LBM18003T. Based on morphological, physiological, biochemical, chemotaxonomic, genotypic and phylogenetic results, strain ZCY20-5T represents a novel species of Caproicibacterium, and the type strain is ZCY20-5T (=MCCC 1A19399T=KCTC 25590T).

Influence of yeast growth conditions and proteolytic enzymes on the amino acid profiles of yeast hydrolysates: Implications for taste and nutrition

This study investigated the effects of aerobic and anaerobic growth and proteolytic enzymes on the amino acid content of yeast hydrolysates in relation to taste and nutrition. Saccharomyces cerevisiae ATCC5574 was grown under fed-batch aerobic or batch anaerobic conditions. Intracellular glutamic acid (Glu) concentrations were 18-fold higher in aerobic yeast.Hydrolysis with papain and alkaline protease released more amino acids (AA) than simple autolysis or hydrolysis with bromelain, most significantly when applied to aerobic yeast (∼2-fold increase). Autolysates and bromelain hydrolysates from aerobic yeast had low levels of bitter and essential AAs, with high levels of umami Glu. Papain and alkaline protease hydrolysates of aerobic yeast had high levels of umami, bitter and essential AAs. Autolysates/hydrolysates from anaerobic yeast had moderate, high, and low levels of bitter, essential and umami AAs.Selection of both yeast growth conditions and hydrolysis enzyme can manipulate the free AA profile and yield of hydrolysates.

Improving the quality of raw milk and yogurt

Milk is a part of many food products. In the expert assessment of the quality of raw materials, primary attention should be paid to its microbiological safety, since poisoning with dairy products is a common cause of diseases of the gastrointestinal tract. The experiment has been carried out on the base in the Teaching and Production Livestock Farm in the Federal State Budgetary Educational Institution of Higher Education “Russian State Agrarian University – Moscow Agricultural Academy named after K. A. Timiryazev” (Moscow). The purpose of the research was to improve the quality indicators of raw milk and yogurt. The method of processing raw milk, which reduces the number of potentially dangerous microorganisms in the products produced from it, has been studied. During the experiment the influence of electromagnetic radiation on organoleptic and physic and chemical parameters has been observed; the quantitative and qualitative composition of milk and yogurt microorganisms has been evaluated. The samples of raw materials had a uniform consistency without sediment and flakes, the color was milky white, and the smell was characteristic of natural cow’s milk. Electromagnetic treatment did not affect the main elements of the chemical composition of milk: the mass fraction of dry substances, fat, protein and lactose. In the experimental samples of raw milk after electromagnetic pulses treatment, the decrease in the growth rate of microorganisms including Quantity of Mesophilic Aerobic and Facultative Anaerobic Microorganisms (QMAFAnM), yeast and mold, has been noted. No bacteria of the Staphylococcus aureus and Escherichia coligroups have been found in the milk samples. The electromagnetic field had the negligible effect on the amount of lactic acid microorganisms in the raw material. During the experiment, there was no negative influence of electromagnetic radiation on the organoleptic, physic and chemical and sanitary-hygienic parameters of yogurt. The issues of ensuring the microbiological safety of raw milk have been described and the method for optimizing the sanitary and hygienic parameters of yogurt in accordance with the current requirements of regulatory documents has been suggest in the article.

Critical parameters and procedures for anaerobic cultivation of yeasts in bioreactors and anaerobic chambers.

ABSTRACTAll known facultatively fermentative yeasts require molecular oxygen for growth. Only in a small number of yeast species, these requirements can be circumvented by supplementation of known anaerobic growth factors such as nicotinate, sterols and unsaturated fatty acids. Biosynthetic oxygen requirements of yeasts are typically small and, unless extensive precautions are taken to minimize inadvertent entry of trace amounts of oxygen, easily go unnoticed in small-scale laboratory cultivation systems. This paper discusses critical points in the design of anaerobic yeast cultivation experiments in anaerobic chambers and laboratory bioreactors. Serial transfer or continuous cultivation to dilute growth factors present in anaerobically pre-grown inocula, systematic inclusion of control strains and minimizing the impact of oxygen diffusion through tubing are identified as key elements in experimental design. Basic protocols are presented for anaerobic-chamber and bioreactor experiments.

Independent Decompositions of Chemical Reaction Networks.

A chemical reaction network (CRN) is composed of reactions that can be seen as interactions among entities called species, which exist within the system. Endowed with kinetics, CRN has a corresponding set of ordinary differential equations (ODEs). In chemical reaction network theory, we are interested with connections between the structure of the CRN and qualitative properties of the corresponding ODEs. One of the results in decomposition theory of CRNs is that the intersection of the sets of positive steady states of the subsystems is equal to the set of positive steady states of the whole system, if the decomposition is independent. Hence, computational approach using independent decompositions can be used as an efficient tool in studying large systems. In this work, we provide a necessary and sufficient condition for the existence of a nontrivial independent decomposition of a CRN, which leads to a novel step-by-step method to obtain such decomposition, if it exists. We also illustrate these results using real-life examples. In particular, we show that a CRN of a popular model of anaerobic yeast fermentation pathway has a nontrivial independent decomposition, while a particular biological system, which is a metabolic network with one positive feedforward and a negative feedback has none. Finally, we analyze properties of positive steady states of reaction networks of specific influenza virus models.

Validation and comparison of aerobic and anaerobic bacteria, yeast and mould detection using the bact/alert® 3D™ and virtuo™ systems for haematopoietic progenitor cells (HPC)

Validation and comparison of aerobic and anaerobic bacteria, yeast and mould detection using the bact/alert® 3D™ and virtuo™ systems for haematopoietic progenitor cells (HPC)

Moment-based dissipative observer design for cell population balance models

Abstract A dissipativity-based observer design for a class of cell population balance models is presented and evaluated using experimental data. The population balance model is described by a partial integro-differential equation coupled with an ordinary differential equation for a batch bioreactor with biomass measurement via an optical density sensor. The dissipative observer is proven to exponentially converge in the first moment of the cell size distribution and the substrate concentration in the absence of modeling and measurement errors. The theoretical results are evaluated using experimental data from a 2 liter lab-scale reactor for anaerobic yeast fermentation on glucose using nitrogen gas supply, showing a good performance of the dissipativity-based estimation scheme.

Devising a technology for making flour from chickpea enriched with selenium

The paper reports results from developing a technology of chickpea flour enriched with selenium. The devised technology would allow the intake of the organic forms of the microelement whose deficiency is suffered by 17 % of the global population. The study has found that the degree of selenium accumulation is affected by the protein content in the native grain. It is rational to use solutions for germination, which are the carriers of 75 μg of selenium. 95...99 % of selenium in sprouted grains are accumulated in the cotyledon, in the protein fraction. During the germination of grains, the amino acid composition increases considerably. The content of leucine, lysine, arginine, and tryptophan increases by 87, 76, 80 %, and 55 %, respectively. The base of the substituted amino acids are aspartic and glutamic acids and their amides, whose share in the non-sprouted grains of chickpea accounts for 67 %, and in the sprouted grains – 70 %. The devised technological protocol of chickpea flour production differs from the control one by that the washing and disinfection of chickpea grains are performed in an aqueous solution of citric acid (pH 3.5...4.0). Afterward, the grains germinate in a solution of NaHSeO 3 for 48 hours. As regards the organoleptic indicators, the proposed flour has a light-yellow color, a smell that is peculiar to chickpea flour, its taste has no bitterness and sour flavors. In terms of its physical-chemical indicators, the differences from control are observed in the mass share of moisture, by 1 % less than that of the control sample, and the mass fraction of fat, which decreases by 2 %. There is a 0.5 % increase in the mass fraction of total ash and the mass fraction of fiber. Regarding the content of mercury, arsenic, lead, the proposed chickpea flour's levels are not higher than those permissible for human consumption; it does not contain cadmium, and its content of copper is less than the permissible level by 1 mg/g. As regards the number of mesophilic aerobic and facultative anaerobic microorganisms, mold fungi, and yeast, the developed chickpea flour is safe for use. It includes neither bacteria from the group of Escherichia coli nor pathogens of bacteria from the genus Salmonella. Our study has allowed us to argue that the developed chickpea flour is a carrier of 52 μg of selenium in the bioavailable organic form that provides 65 % of daily requirement in selenium for an adult healthy person

A computational approach to multistationarity of power-law kinetic systems

This paper presents a computational solution to determine if a chemical reaction network endowed with power-law kinetics (PLK system) has the capacity for multistationarity, i.e., whether there exist positive rate constants such that the corresponding differential equations admit multiple positive steady states within a stoichiometric class. The approach, which is called the "Multistationarity Algorithm for PLK systems" (MSA), combines (i) the extension of the "higher deficiency algorithm" of Ji and Feinberg for mass action to PLK systems with reactant-determined interactions, and (ii) a method that transforms any PLK system to a dynamically equivalent one with reactant-determined interactions. Using this algorithm, we obtain two new results: the monostationarity of a popular model of anaerobic yeast fermentation pathway, and the multistationarity of a global carbon cycle model with climate engineering, both in the generalized mass action format of biochemical systems theory. We also provide examples of the broader scope of our approach for deficiency one PLK systems in comparison to the extension of Feinberg's "deficiency one algorithm" to such systems.

RESEARCH OF THE SAFETY INDICATORS OF BERRY SAUCES WITH SEAWEED’S RAW MATERIALS

The current thing now is the matter regarding enrichment of food products with organic iodine, which is caused by iodine deficiency in the food ration of most of the country's population and by the country-wide radionuclide pollution, which leads to a hundredfold increase of risks of the thyroid body radiation. In this regard, there were developed the technologies of the berry sauces with the addition of the seaweed’s raw materials, as the iodine-concentrating component. The technologies of blueberry-cranberry sauces with guelder-rose juice, cornel-bilberry sauce with guelder-rose juice and blueberry-buckthorn sauce with guelder-rose juice were developed. This work is dedicated to a research of safety indicators of the developed sauces. There were used the hydrated seaweeds of Laminaria, of Fucus, of Undaria pinnatifida as iodinated additives. The following microbiological indicators were determined: the quality of mesophilic aerobic and optionally anaerobic microorganisms (МAOАnM), mold, yeast and lactic acid bacteria, and the presence of the coliform bacteria (CB) bacteria. The study results showed, that there are no microorganisms in the finished products, which may result the damage of the product after pasteurization. It was identified, that the own organic acids of the prepared sauces will be sufficient to ensure the microbiological clearness and the use of the additional preserving agents does not make sense. Toxicological indicators, namely the mass fractions of lead, cadmium, arsenic and mercury, have been studied. It has been established that the content of toxic elements in test samples is hundreds of times less than permissible. The toxicological indicators were studied, namely, the mass fractions of lead, cadmium, arsenic and mercury. It was identified, that the content of toxic elements in test samples is hundreds of times less than permissible. Thus, it is proved that the sauces made according to the developed technology, comply with the requirements of the regulatory documents according to the safety indicators. Moreover, it is proved, that that the addition of the seaweed’s raw materials does not worsen these indicators. To confirm the obtained data, the sample with the highest seaweed content was examined by an independent laboratory accredited according to DSTU ISO/IEC 17025 with the issuance of the appropriate test report.

Photoheterotrophy of photosynthetic bacteria ( Rhodopseudomonas palustris ) growing on oil palm and soybean cooking oils

Abstract Cooking oil wastes are environmentally damaging and costly to deal with. Photoheterotrophic growth of Rhodopseudomonas palustris (photosynthetic bacteria) (CGA 009) was used to decompose different types of cooking oil (palm and soybean oils; cooked and uncooked palm oil) under anaerobic and microaerobic conditions. Photosynthesis was measured in R. palustris using PAM technology (Pulse Amplitude Modulation Fluorometry): Optimum irradiance ≈ 284 μ mol photon m−2 s−1 and maximum photosynthetic electron transport rate (ETR) ≈ 341 μ mol e − g−1 BChl a s−1. R. palustris grew photoheterotrophically on both cooking oils as the sole carbon source grown anaerobically and microaerobically in PM media with a NH3-nitrogen source. R. palustris grew well on used palm oil. R. palustris produces small volumes of hydrogen gas from biodegradation of oil but only under nitrogen fixing conditions (anaerobic: no ammonia or organic nitrogen). N-fixing cells grew very slowly. Cooking oil waste residues are also produced at the production stage (Palm Oil Milling Effluent, POME) and in recycling them for reuse or to produce biodiesel. Hence, biodegradation of cooking oil wastes is an important issue at the production, domestic consumption and recycling stages of their use. A two-stage digestion using an anaerobic yeast first stage, followed by a R. palustris digestion was feasible. Two Line Capsule: The photosynthetic bacterium R. palustris grows photoheterotrophically on Palm Oil and Soybean Oil. Photosynthetic rates were measured using PAM technology.

Binary Interactions of Antagonistic Bacteria with Candida albicans Under Aerobic and Anaerobic Conditions.

We used both aerobic and anaerobic liquid co-cultures, prepared with Luria Bertani broth, to study the effect of bacteria on the survival of Candida albicans in the external environment, away from an animal host. The bacteria were represented by Aeromonas hydrophila, Bacillus cereus, Bacillus subtilis, Clostridium, Enterobacter, Klebsiella pneumoniae, Kluyvera ascorbata and Serratia marcescens. Under aerobic conditions, the yeast's growth was inhibited in the presence of bacterial growth; however, under anaerobic conditions, yeast and bacterial growth in co-cultures was similar to that observed for pure cultures. Subsequent assays revealed that the majority of bacterial strains aerobically produced extracellular hydrolytic enzymes capable of yeast cell wall hydrolysis, including chitinases and mannan-degrading enzymes. In contrast, except for the A. hydrophila strain, these enzymes were not detected in anaerobic bacterial cultures, nor was the antimicrobial compound prodigiosin found in anaerobic cultures of S. marcescens. When we suspended C. albicans cells in crude extracellular enzyme preparations from K. pneumoniae and S. marcescens, we detected no negative effect on yeast viability. However, we found that these preparations enhance the toxicity of prodigiosin towards the yeast, especially in combination with mannan-degrading enzymes. Analyses of the chitin and mannan content of yeast cell walls revealed that less chitin was produced under anaerobic than aerobic conditions; however, the levels of mannan, known for its low permeability, remained the same. The latter phenomenon, as well as reduced production of the bacterial enzymes and prodigiosin, may contribute to anaerobic growth and survival of C. albicans in the presence of bacteria.

Oxygen availability strongly affects chronological lifespan and thermotolerance in batch cultures of Saccharomyces cerevisiae.

Stationary-phase (SP) batch cultures of Saccharomyces cerevisiae, in which growth has been arrested by carbon-source depletion, are widely applied to study chronological lifespan, quiescence and SP-associated robustness. Based on this type of experiments, typically performed under aerobic conditions, several roles of oxygen in aging have been proposed. However, SP in anaerobic yeast cultures has not been investigated in detail. Here, we use the unique capability of S. cerevisiae to grow in the complete absence of oxygen to directly compare SP in aerobic and anaerobic bioreactor cultures. This comparison revealed strong positive effects of oxygen availability on adenylate energy charge, longevity and thermotolerance during SP. A low thermotolerance of anaerobic batch cultures was already evident during the exponential growth phase and, in contrast to the situation in aerobic cultures, was not substantially increased during transition into SP. A combination of physiological and transcriptome analysis showed that the slow post-diauxic growth phase on ethanol, which precedes SP in aerobic, but not in anaerobic cultures, endowed cells with the time and resources needed for inducing longevity and thermotolerance. When combined with literature data on acquisition of longevity and thermotolerance in retentostat cultures, the present study indicates that the fast transition from glucose excess to SP in anaerobic cultures precludes acquisition of longevity and thermotolerance. Moreover, this study demonstrates the importance of a preceding, calorie-restricted conditioning phase in the acquisition of longevity and stress tolerance in SP yeast cultures, irrespective of oxygen availability.

Anhydrobiosis in yeast: is it possible to reach anhydrobiosis for yeast grown in conditions with severe oxygen limitation?

The yeast Saccharomyces cerevisiae was shown to be extremely sensitive to dehydration-rehydration treatments when stationary phase cells were subjected to conditions of severe oxygen limitation, unlike the same cells grown in aerobic conditions. The viability of dehydrated anaerobically grown yeast cells never exceeded 2%. It was not possible to increase this viability using gradual rehydration of dry cells in water vapour, which usually strongly reduces damage to intracellular membranes. Specific pre-dehydration treatments significantly increased the resistance of anaerobic yeast to drying. Thus, incubation of cells with trehalose (100mM), increased the viability of dehydrated cells after slow rehydration in water vapour to 30%. Similarly, pre-incubation of cells in 1M xylitol or glycerol enabled up to 50-60% of cells to successfully enter a viable state of anhydrobiosis after subsequent rehydration. We presume that trehalose and sugar alcohols function mainly according to a water replacement hypothesis, as well as initiating various protective intracellular reactions.

Determination of shelf life of marinated carp fillets

In the present study, sensory, microbiological and chemical changes during manufacturing and storage of marinated and baked fillets were investigated. For this purpose, the fillets were divided in to three groups. One group was control and the other two groups were marinated with two different marination mixes (group A and group B). The control fillets were cooked at 150?C for 55 minutes. The marinated groups were cooked after holding at +4?C for 6 hours. Central temperatures of cooked fillets were chilled to +4 ?C and vacuum packaged. Vacuumed fillets stored at +4?C. Then fillets were analysed for sensory, microbiological (mesophilic aerobic bacteria, psycrophilic aerobic bacteria, mesophilic anaerobic bacteria, yeast and mould counts) and chemical (pH, moisture, total volatile - nitrogen, tiobarbituric acid and salt) on 0, 7 th,14 th,28 th,42 nd,56 th,70 th,84 th and 98 th days of storage. In the microbiological analysis, counts of total mesophilic aerobic bacteria, psycrophilic aerobic bacteria, mesophilic anaerobic bacteria, yeast and mould counts were determined as < 10 cfu/g in all groups during the storage. There was no significant difference among the groups in pH, moisture, TVB-N and salt level (p>0.05). The TBA value increased during the storage period in control group. As for the TBA value, the difference between control group and group A and group B was significant (p<0.05). When fillets have been investigated from sensory characteristics, A and B products found beter than control group throughout the storage period.

Gene expression divergence in yeast is coupled to evolution of DNA-encoded nucleosome organization.

Eukaryotic transcription occurs within a chromatin environment, whose organization has an important regulatory function and is partly encoded in cis by the DNA sequence itself. Here, we examine whether evolutionary changes in gene expression are linked to changes in the DNA-encoded nucleosome organization of promoters. We find that in aerobic yeast species, where cellular respiration genes are active under typical growth conditions, the promoter sequences of these genes encode a relatively open (nucleosome-depleted) chromatin organization. This nucleosome-depleted organization requires only DNA sequence information, is independent of any cofactors and of transcription, and is a general property of growth-related genes. In contrast, in anaerobic yeast species, where cellular respiration genes are relatively inactive under typical growth conditions, respiration gene promoters encode relatively closed (nucleosome-occupied) chromatin organizations. Our results suggest a previously unidentified genetic mechanism underlying phenotypic diversity, consisting of DNA sequence changes that directly alter the DNA-encoded nucleosome organization of promoters.

Anaerobic yeast fermentation for the production of ethanol in a versatile lab fermentor

Whether used for research or production, the versatile BioFlo® 310 fermentor from New Brunswick Scientific allows growth of a wide variety of aerobic and anaerobic microorganisms, including bacteria, plant, algae, fungi and yeast. Its advanced controller can regulate up to four vessels simultaneously, 120 process loops in all. Here we demonstrate one facet of its versatility—a technique for inducing ethanol production in yeast, by switching from an aerobic growth phase to an anaerobic steady-state culture.

혐기성 박테리아, 효모 및 곰팡이로 제조된 synbiotics의 첨가가 축우용 완전혼합사료의 호기적 안전성에 미치는 영향

This study was conducted to investigate the effects of supplementation of synbiotics manufactured with anaerobic bacteria, yeast and mold on preservation of total mixed ration (TMR) by exposing days. Eight treatments were composed of untreated synbiotics(US), bacterial synbiotics (BS), yeasty synbiotics (YS), moldy synbiotics (MS), bacterial and mouldy synbiotics (BMS), yeasty and moldy synbiotics (YMS), bacterial and yeasty synbiotics (BYS), and bacterial, yeasty and moldy synbiotics (BYMS). After 7 days of anaerobic fermentation, fermented-TMRs were exposed to the air during 1, 3, 5, 7, 14 and 21 days. One hundred forty four (8 treatments6 days3 replications) fermented-TMRs were manufactured by vinyl bag (). Although no significant differences in the activities of carboxymethylcellulase, xylanase and amylase were observed among treatments, theirs acivities were seemed to increase by treatment of BYS or YMS containing yeast. Total bacterial and mold counts also decreased in the treatments containing yeast. Potential pathogenic bacteria were less detected in BYS and BMYS for E. coli, BMYS and YS for Salmonella, and BMS and BMYS for Shigella than those of the other treatments, MS was, however, contaminated easier than US by pathogenic bacteria. From above results, synbiotics containing facultative anaerobic yeast have effects for preservation of TMR fermented anaerobically. Particularly, BMYS treatment having good results in nutrient contents, dry matter loss and pathogenic bacteria amounts was a resonable synbiotics for preservation of the fermented-TMR.

Anaerobic Immobilized Yeast Cell Fermentation and Anaerobic Remediation in Hybrid Reactor for Mineralization of Dicarboxylic Acid Solid Waste

The solid resinous product (SRP) containing unsaturated/saturated dicarboxylic acid residues, phthalic acid and maleic acid is discharged as a solid waste during cracking of benzene over vanadium at temperatures above 500°C in the dicarboxylic acid manufacturing industry. In the present study the solid waste was diluted with water to a concentration of 0.5% w/v for microbial degradation. The waste was fermented in a reactor containing mesoporous activated carbon on which was immobilized Saccharomyces cerevisiae at an optimum residence time of 24 h at pH 6.5. The immobilized-yeast-treated samples were further treated in an upflow anaerobic reactor at an hydraulic retention time (HRT) of 0.1038 days at a hydraulic flow rate of 7.34 × 10−3 m3/day and chemical oxygen demand (COD) loading rate of 2.19 kg/m3/day. The pathway followed in the degradation of dicarboxylic acid into end products by anaerobic metabolism in the yeast cell fermentor and in the upflow anaerobic reactor was confirmed through HPLC, Fourier transform infra red spectroscopy and proton and 13C NMR spectroscopy.