Type Of Inoculum Research Articles

The best type of inoculum for testing the antifungal drug susceptibility of Microsporum canis: In vivo and in vitro results.

Data correlating in vitro drug susceptibility of Microsporum canis with clinical outcomes of its infections are lacking as well as the most suitable inoculum and incubation time in broth microdilution assays. Microsporum canis strains were collected from animal hosts that tested positive (Group I; n=13) and negative (Group II; n=14) to this pathogen following itraconazole (ITC) therapy. In vitro ITC susceptibility was assessed according to the Clinical Laboratory Standards Institute (CLSI M38-A2) methodology using conidia, hypha-conidia and arthroconidia at 3 and 7days of incubation in order to assess the most suitable inoculum and incubation time. Successively, ketoconazole (KTC), voriconazole (VRC), terbinafine (TRB), posaconazole (PSZ), fluconazole (FLC) and griseofulvin (GRI) susceptibilities were assessed using the chosen inoculum. The MIC values of ITC after three-day incubation were equal than those recorded after 7-day incubation. Itraconazole MICs were ≤1μg/mL for strains from Group II and >1μg/mL for those of Group II only when conidia were used. All strains showed high susceptibility to VRC, POS, TEB and low susceptibility to ITC, KTC, GRI and FLC regardless of the source and incubation time. Results suggest that correlation between the in vitro results and clinical outcome was observed only by incubating conidia for 3days at 30±2°C. These conditions might be most suitable to assess in vitro susceptibility of M.canis and assist in determining the occurrence of drug resistance and cross-resistance phenomena.

Effects of woody biochar on dry thermophilic anaerobic digestion of organic fraction of municipal solid waste

This study presents the results of semi-pilot scale anaerobic digestion tests conducted under dry thermophilic conditions with the addition of biochar (6% on fresh mass basis of inoculum), derived from an industrial gasification plant, for determining biogas and biomethane production from organic fraction of municipal solid waste. By using two types of inocula (from a full-scale dry anaerobic digestion plant and from lab-scale biomethanation tests), the obtained experimental results did not show significant increase in methane yield related to the presence of biochar (330.40 NL CH4 kgVS−1 using plant inoculum; 335.41 NL CH4 kgVS−1 using plant inoculum with biochar, 311.78 NL CH4 kgVS−1 using lab-inoculum and 366.43 NL CH4 kgVS−1 using lab-inoculum with biochar), but led to significant changes in the microbial community composition. These results are likely related with the specific biochar physical-chemical features and low adsorption potential.Resulting digestate quality was also investigated: biochar-enriched digestates were characterized by increased biological stability (809 ± 264 mg O2 kgVS−1 h−1 vs. 554 ± 76 mg O2 kgVS−1 h−1 for biochar-free and biochar-enriched digestates, respectively), lower heavy metals concentrations (with the exception of Cd), but higher polycyclic aromatic hydrocarbons content, with a reported maximum concentration of 8.9 mgPAH kgTS−1 for biochar-enriched digestate derived from AD test with lab-inoculum, which could trigger non-compliance with regulation limits for agricultural reuse of digestates. However, phytotoxicity assessments showed a decreased toxicity of biochar-containing digestates when compared to biochar-free digestates.

Production of Conidia by Entomopathogenic Fungi and Their Pathogenicity Against Coptotermes sp.

Entomopathogenic fungi have the potential to infect most arthropods including termites which are economically important major insects pest of wood, wood products and building structures. However, the application of this fungus in the field has not shown satisfactory results yet, one of which is constrained in mass production of conidia. The purpose of this study was to evaluate 16 types of biodegradable products and waste as substrates for mass production of conidia using solid state fermentation method and two types of inoculum namely solid and liquid inoculum. Toxicity tests were carried out on subterranean termites (Coptotermes sp.) based on JIS K 1571, 2010. The parameters observed were the number and dry weight of the conidia produced, conidial viability, nutrient content of the substrate, and percentage of termite mortality. The results showed that rice, sorghum and corn were the best media for the growth of entomopathogenic fungi based on the number of conidia and dry weight of the conidia produced. Metarhizium sp. T4.B23 produced the highest number of conidia, 1.12 x 1011 conidia/100 g substrate and yielded 180.9 ± 0.623 g dry conidia/kg of rice; followed by Metarhizium sp. B2.2 grown on sorghum that resulted in 1.11 x 1010 conidia/100 g substrates and 8 ± 0.570 g /kg sorghum; and B. bassiana produced 8.3 x 109 conidia/100 g substrate and 31.24 ± 0.407 gr/ kg sorghum. Metarhizium sp. B2.2 showed the highest toxicity to termites with 100% mortality was observed within the second day of testing. Therefore the conidia of Metahizium sp. B2.2 is potential to be developed as a biopesticide using rice or sorghum substrate as a carrier.

Aryl Diazonium Modification on Graphite Electrode in Microbial Fuel Cell: A Review

Usage of graphite electrode in a microbial fuel cell (MFC) is favored due to their electron conductivity and stability as a base material for the electrode. Also, graphite is favored as it allows the growth of biofilm, which can enhance the cell’s performance. The efficiency is reported improved through modification. Aryl diazonium modification has been reported to induce biofilm formation on the electrode faster. The modification can be done spontaneously or through electrografting of aryl diazonium salt onto the electrode surface. Control over the quantity of grafted aryl diazonium is essential. A thick layer will cause the performance of the system to drop, which may impede the electron transfer from biofilm to the electrode. Aryl diazonium is preferred as it allows a robust biofilm formation when used as a surface modification on the graphite electrode. Modification using aryl diazonium allows the electrode to be more accommodative for biofilm growth, which will increase the performance of the system. However, it does not act as a redox mediator for the system. It has been reported that power density obtained using aryl diazonium modified electrode is 250 mW.m-2, higher than unmodified graphite electrode of 125 mW.m-2. However, not all bacterial species is compatible with aryl diazonium modification. The unmodified graphite biocathode allows a higher power density compared to aryl diazonium modified biocathode. Hence, depending on the quality of aryl diazonium modification and the types of inoculum used, MFC performance can be further maximized.

Oxygen as a key parameter in in vitro dynamic and multi-compartment models to improve microbiome studies of the small intestine?

In vitro digestion and fermentation models are frequently used for human and animal research purposes. Different dynamic and multi-compartment models exist, but none have been validated with representative microbiota in the distal parts of the small intestine. We recently developed a dynamic and multi-compartment piglet model introducing microbiota in an ileum bioreactor. However, it presented discrepancies compared to in vivo data. Recommendations are available to standardize studies in this field. They target the digestion model but include elements of a fermentation model. But no recommendation is given concerning control of the atmosphere. The gastrointestinal tract is generally associated with anaerobiosis to conduct a good fermentation process. In this study, we attempted to improve the ileal microbiota of the piglet model by testing inoculation: real intestinal content vs feces; the latter being generally used for ethical and economical aspects. Results showed a positive effect of using real intestinal content. Fusobacteriia were less abundant in the model, Bacteroidia were better maintained in the colon. But for the ileum, results showed that anoxic conditions in the ileum bioreactor conditioned the microbial profile probably more than the type of inoculum itself, leading to the general conclusion that in vitro dynamic and multi-compartment models probably have to get oxygenated to improve microbiome studies of the small intestine.

Assessment of Process Variables on Vitamin B12 Production in Fermented Dairy Product Including Propionic Acid

The fermented dairy products produced by various microorganism’s activity provide valuable nutrients for human. Fermentation affects the physicochemical and organoleptic characteristics of foods as well as human health. In the present review, we describe the production of vitamin B12 in a fermented dairy product by Propionibacterium species. The effect of the process variables on vitamin B12 production in fermented dairy products e.g. pH, temperature, different carbon and nitrogen sources as well as the type and size of inoculum, the fermentation time and fermentation strategy, etc. are discussed. Finally, fermentation strategy, inoculum preparation of Propionibacterium freudenreichii subsp. Shermanii, methods of determining biomass and Vitamin B12 concentration are reviewed and their effects on vitamin B12 production are mentioned. Propionibacteria are so popular due to their unique characteristics such as being safe, convenient and economical. Among all the highest efficiency was observed by P. freudenreichii. To achieve this purpose, some appropriate situations need to be considered. The best carbon source for this bacterium to produce biomass is lactate, the suitable pH for growth of the Propionibacterium species is in the range of 6 to 7 and the fed-batch is most preferable for vitamin B12 production.

Obtención de alcohol etílico a partir de dos variedades de cabuya: alternativa para su industrialización

Este proyecto de investigación estudia la utilización de plantas nativas de Furcraea cabuya var. integra y Furcraea cabuya var. cabuya del litoral ecuatoriano, cosechadas en los poblados de: Ayampe, Montecristi, Tosagua, Portoviejo, con el objetivo principal de obtener alcohol etílico mediante la fermentación, destilación y filtración y de esta forma conseguir una bebida alcohólica apta para el consumo humano. En el acondicionamiento y desarrollo experimental se consideran los diferentes parámetros como los diferentes tiempos y temperaturas de cocción, las pruebas con diferentes tipos de inóculos y concentraciones de levaduras, además de diferentes suplementaciones nutritivas (con especial atención a la fuente de nitrógeno). Estableciendo como temperatura óptima para la hidrólisis de la inulina 117 °C durante 4 horas y el proceso fermentativo óptimo utilizando levadura seca activa comercial al 1% p/v con respecto al mosto y una suplementación con sulfato de amonio de 0,15 g/100mL de mosto. El mosto de cabuya rectificado genera una bebida con exquisito sabor a Tequila, la cual luego de ser evaluada sensorialmente demostró que el licor producido se encuentra dentro de los parámetros de aceptación de los consumidores. Palabras clave: etanol, cabuya, destilación, fermentación, mosto, tequila.

Inoculation and habitat amelioration efforts in biological soil crust recovery vary by desert and soil texture

As dryland degradation continues, it is increasingly important to understand how to effectively restore biocrust communities. Potential techniques include the addition of biocrust inoculum to accelerate biocrust recovery. Enhanced erosion typical of degraded environments creates a challenge for these approaches, due to loss by wind or water and burial by saltating particles. To retain and protect added inoculum, the inclusion of habitat‐amelioration techniques can improve recovery rates. This study tested three different types of inoculum (field‐collected, greenhouse‐cultivated, and laboratory‐cultivated biocrust) coupled with two treatments to augment soil stability and ameliorate habitat limitations: soil surface polyacrylamide additions and installation of straw barriers. This was done across two deserts (Great Basin and Chihuahuan) and separated into generally coarse‐ or finer‐textured soils in each desert, with results monitored for 3 years (2015, 2016, 2017). While the inoculum type, coupled with habitat ameliorations, occasionally enhanced biocrust growth across years and treatments, in other cases, it made no difference compared to natural recovery rates. Rather, the desert location and soil texture groupings were the most prominent factors in determining recovery trajectories. Recovery proportions were similar in the finer‐textured sites in both the Great Basin and the Chihuahuan deserts, while the coarser‐textured site in the Great Basin did show some recovery over time and the Chihuahuan coarser‐textured site did not. This study demonstrates the importance of understanding site potential and identifying key limitations to biocrust recovery for successful restoration projects.

In vitro fermentation outcomes of arabinoxylan and galactoxyloglucan depend on fecal inoculum more than substrate chemistry.

Using in vitro fermentation conditions, this study investigated the fermentation characteristics of arabinoxylan (AX) and xyloglucan (XG) with a fecal inoculum that was collected either from humans consuming unrestricted diets or pigs fed a semi-defined diet with cellulose being the sole non-starch polysaccharide for 10 days prior to fecal collection. Metagenomic analysis revealed that microbial communities in the two types of inoculum were distinctively different, which led to distinct fermentation characteristics with the polysaccharides. The microbial communities fermented with the porcine fecal inoculum were clustered according to the fermentation time, while those fermented with the human fecal inoculum were differentiated by the substrates. Using the porcine fecal inoculum, irrespective of the substrates, Prevotella copri and the unclassified lineage rc4-4 were the dominant operational taxonomic units (OTUs) promoted during fermentation. Fermentation of wheat AX (WAX) and galacto-XG (GXG) with the human fecal inoculum, however, promoted different OTUs, except for a shared OTU belonging to Lachnospiraceae. Specifically, WAX promoted the growth of Bacteroides plebeius and a Blautia sp., while GXG promoted an unclassified Bacteroidales, Parabacteroides distasonis, Bacteroides uniformis and Bacteroides sp. 2. These changes in bacterial communities were in accordance with the short chain fatty acid (SCFA) production, where comparable SCFA profiles were obtained from the porcine fecal fermentation while different amounts and proportions of SCFA were acquired from fermentation of WAX and GXG with the human fecal inoculum. Altogether, this study indicated that the starting inoculum composition had a greater effect than polysaccharide chemistry in driving fermentation outcomes.

Effect of the process conditions on the anaerobic fermentation of glucose for the production of chemicals

In the context of biorefinery for the production of chemicals, this study optimised the processes to enhance the anaerobic production of ethanol and short-chain organic acids from glucose. The optimised variables included (with a total of 49 runs) residence time (2–100 h), temperature (25–35 °C), type of inoculum (soil or anaerobic digester), presence or absence of pre-acclimation of the inoculum, glucose concentration (5–50 g/L), continuous or batch mode and composition of the mineral media (mineral solution with or without trace elements, with deionised or tap water). In continuous experiments, the residence time was the most important parameter that affected glucose conversion (over 80% glucose conversion for residence time longer than 30 h) and product yields (ethanol was the main product in the range of residence times 20–50 h, with yields in the range 0.30–0.40 g/g glucose removed). Temperature, type of inoculum, and pre-acclimation had little effect on glucose conversion and products yield. The addition of trace elements had an important beneficial effect on the removal of glucose when it was fed at the highest concentration (50 g/L) in both continuous and batch experiments. In batch runs, acetate was generally the main fermentation product rather than ethanol and ethanol conversion into acetate was favoured by nitrogen sparging, probably due to the reduced hydrogen partial pressure.

Variability in the Response of Bacterial Community Assembly to Environmental Selection and Biotic Factors Depends on the Immigrated Bacteria, as Revealed by a Soil Microcosm Experiment.

Exploring the assembly mechanism of microbiota is critical for understanding soil ecosystem functions. However, the relative importance of different biotic and abiotic factors in determining the bacterial community has not been properly clarified. In this study, the effects of inocula and recipients on the assembly of the soil community were investigated to evaluate their importance by inoculation experiments with sterile soil. Two distinct soils, conventional nitrogen-fertilized soil and aromatic-compound-contaminated soil, were sterilized, cross inoculated, and incubated for 2 months under different inoculation doses and oxygen conditions. The results showed that the greatest variation in community structure emerged in the samples inoculated with distinct inocula rather than in the samples of different soil recipients. The phylogenies in the two inocula were diverse and dissimilar, although there were many ecologically equivalent bacteria. When the inocula with dissimilar ecologically equivalent species were used, the assembled communities were primarily determined by the inocula as indicated by the beta diversity and variation partitioning analyses. In contrast, environmental selection dominated the process when ecologically equivalent species in the inocula were similar, as when only one type of inoculum was used, where the soil habitat selected the most adaptive bacteria from the defined inoculum pool. These results indicate that inoculated bacteria are dominant over environmental selection if they are sufficiently dissimilar, although the effect of environmental selection is more obvious when similar bacteria are inoculated in the soil for community assembly. Our findings suggest that the immigration of exotic bacteria could be a primary factor impacting community assembly.IMPORTANCE The soil microbiota conducts important biological ecosystem functions, but the mechanism underlying community-environment interactions for soil microbiota remains unclear. By using two distinct soils for cross inoculation, we successfully simulated the assembly of the bacterial community in sterile soil. Thus, the reasons why inoculum and recipient have dominated community assembly in previous investigations are investigated in this study. We found that inoculated bacteria presided over environmental selection for community assembly due to the varied difference of ecological equivalent bacteria, either divergent or convergent. The significance of neutrality for the ecologically equivalent bacterial species that immigrated into the recipients should be emphasized in exploring the mechanisms of community assembly. Our finding is helpful for understanding the community-environment interaction, a basic question in ecology, and it would shed light on this issue that has perplexed scientists for many years.

Preliminary evaluation of the anaerobic biodegradability of three biobased materials used for the production of disposable plastics

Biodegradable plastics have been introduced to the market to substitute “traditional”, non-biodegradable, petro-based plastics to alleviate plastic pollution. Biochemical methane potential tests were carried out on compostable bags made of MaterBi®, biodegradable bottle wine corks and cellulosic plates to examine the anaerobic biodegradability of those materials. The impact of four factors: type of pretreatment (predigestion, mechanical, alkaline, predigestion and alkaline), digestion duration, type of inoculum and temperature were statistically evaluated through regression modeling. Anaerobic tests on compostable and polyethylene bags (control) were carried out in mesophilic (35 °C) and thermophilic (55 °C) conditions, while tests on bottle wine corks and cellulosic plates were carried out in mesophilic conditions only. After 15 days of digestion, a dry mass reduction of 22.8 ± 6.2 % and 27.6 ± 14.0 % for mesophilic and thermophilic tests respectively was recorded for MaterBi®. Chemical pretreatment with NaOH led to a mass reduction of 78.2 ± 7.2 % and was the only statistically significant factor to affect both methane yields and dry mass loss. A higher digestion temperature led to an increased mass loss without a concurrent increase in methane production. The cellulosic plates were completely degraded (99.9 ± 0.03 % mass reduction), while the wine bottle corks weight did not change.

Organic acids produced during fermentation and sensory perception in specialty coffee using yeast starter culture.

Volatile and non-volatile compounds in coffee directly affect the beverage's quality. This study aimed to demonstrate how the organic acids and volatile profiles were impacted by coffee fermentation using four starter cultures (Meyerozyma caribbica (CCMA 0198), Saccharomyces cerevisiae (CCMA 0543), Candida parapsilosis (CCMA0544), and Torulaspora delbrueckii (CCMA 0684)) inoculated in two varieties of coffee (Bourbon Amarelo and Canário Amarelo) using natural and pulped natural processing methods and sensory perception. Real-time PCR (qPCR) was used to verify the dynamic behavior of yeast populations. Organic acids were detected using high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) was used to detected volatile compounds. Sensory analysis was performed on the roasted coffee. Citric, malic, succinic, lactic, oxalic, isobutyric, and propionic acids and 105 volatile compounds were detected. At the beginning of fermentation, treatments with natural processing presented higher number of volatiles compounds. After fermentation, the main compounds groups were acids, alcohols, and aldehydes. The perception of sensory attribute (fruity, nutty, cocoa) varied with the coffee variety, type of processing, and type of inoculum. The use of yeasts is an alternative for sensorial differentiation of coffee variety Canário Amarelo and Bourbon Amarelo. The stainless-steel containers showed good results for coffee fermentation.

Comparison of Faecal versus Rumen Inocula for the Estimation of NDF Digestibility

Simple SummaryThe evaluation of fibre digestibility is very important for the formulation of ruminant diets. Fibre digestibility is usually determined in lab with rumen inoculum obtained from cannulated cows. The research of alternative and less invasive inoculum sources is a critical issue that should be addressed. The present study evaluated the potential of faecal inocula, obtained from cows fed different diets, to assess fibre digestibility of different substrates at different incubation times (48, 240 and 360 h). At short incubation time, fibre digestibility obtained with rumen fluid was always higher than those obtained with faecal inocula, confirming a lower activity of the faecal inocula compared with rumen fluid. However, the type of diets fed to the donor animals had a significant effect on fibre digestibility, with a more active faecal inoculum for cows fed a diet based on maize silage. Despite the differences obtained at the short incubation time, the digestibility values at longer intervals showed that faecal inoculum could replace rumen inoculum. As a consequence, faeces may replace rumen fluid as inoculum for end-point measures, avoiding the use of cannulated animals and decreasing the analytical costs.Cow faeces have been investigated as alternative inoculum to replace rumen fluid to determine neutral detergent fibre (NDF) digestibility (NDFD). Aims of this study were to estimate: (1) the NDFD (48 h) of feed ingredients using a rumen inoculum in comparison with faecal inocula from cows fed diets with different forage basis; (2) the undigestible NDF (uNDF) at 240 and 360 h with ruminal fluid and faecal inocula from lactating cows fed two different diets. At 48 h incubation, the NDFD was affected both by feed and type of inoculum (p < 0.01) and by their interaction (p = 0.03). Overall, the mean NDFD was higher for rumen inoculum than for faecal inocula (585 vs. 389 g/kg NDF, p < 0.05), and faecal inoculum obtained from cows fed hay-based diets gave lower NDFD than those from cows fed maize silage (367 vs. 440 g/kg, p < 0.05). At long incubation times, the average uNDF was affected by substrate, inoculum and incubation time (p < 0.01), but not by their interactions. For each inoculum, significantly lower values were obtained at 360 than at 240 h. Regressions between uNDF with rumen and with the tested faecal inocula resulted in r2 ≥ 0.98. Despite the differences at 48 h, the uNDF showed that faecal inoculum could replace rumen fluid at longer incubation times.

Pepper (Capsicum ssp.) as a feed additive in sheep rations using two types of inoculum: Effects on in vitro digestibility and fermentation parameters

The influence of pepper (Capsicum ssp.) as a feed additive to balanced sheep rations on the in vitro digestibility coefficient of nutrients and their fermentation parameters was evaluated in two different inocula: rumen liquid and sheep feces. Four inclusion levels of pepper (0.0%, 0.2%, 0.4% and 0.6% of DM) and two types of inoculum were arranged in a 4 x 2 factorial arrangement, in a completely randomized design. Experimental rations were balanced to include 0.0%; 0.2%; 0.4% and 0.6% Capsicum ssp., with 13.5% crude protein and 70.0% total digestible nutrients (TDN). A basal diet of 60% bulk (corn silage) and 40% of the concentrate containing 0.0% Capsicum ssp. was given to the inoculant donor animals. Two sheep with a mean bodyweight of 27.6 + 1.6 kg were used as inoculum donors (ruminal fluid and feces) for the determination of the IVDC of nutrients. The variables studied were submitted for analysis of variance and the inclusion levels of pepper. Regression analysis was performed at 5% of probability and for the different inocula, a Tukey test was performed at 5% significance. The different levels of inclusion of pepper (0.0%, 0.2%, 0.4%, and 0.6%) in the balanced sheep rations were not altered (P &gt; 0.05) the IVDC of DM; OM; CP and NDF for both inocula (ruminal fluid and sheep feces). However, the use of the different inocula resulted in a change (P &lt; 0.05) in the IVDC value of DM, OM, CP, and NDF, in which the ruminal liquid inoculum presented higher (P &lt; 0.05) values of IVDC for the ration nutrients in relation to sheep feces. The levels of 0, 0%; 0.2%; 0.4% and 0.6% of pepper in ruminant feeds did not change the pH value of the fermented content after a 24-hour in vitro incubation (P &gt; 0.05). However, the use of ruminal liquid as inoculum for the in vitro fermentation of the experimental rations provided a lower value (P &lt; 0.05) for the pH of the fermented content in relation to the sheep feces. The inclusion of this phytogenic additive in ruminant feeds and the use of inoculum based on rumen fluid or sheep feces did not cause changes in the concentration of ammoniacal nitrogen (N-NH3) in the fermented rations after incubation (P &gt; 0.05) for 24 hours in vitro. Thus, the inclusion of up to 0.6% Capsicum ssp. (pepper) in balanced rations for ruminants does not alter the in vitro digestibility coefficient of dry matter, organic matter, crude protein, and neutral detergent fiber, or the in vitro fermentation parameters. However, the use of ruminal fluid as inoculum for the in vitro fermentation presented values of a higher degree of confidence in relation to feces to determine the in vitro digestion coefficient of the nutrients.

Rumen Inoculum Collected from Cows at Slaughter or from a Continuous Fermenter and Preserved in Warm, Refrigerated, Chilled or Freeze-Dried Environments for In Vitro Tests.

Simple SummaryThe utilization of animal donors of rumen fluid for laboratory experiments can raise ethical concerns due to invasive methods of collection (rumen cannulated or intubated animals). Societies are strongly oriented to support cruelty free experiments and alternatives to the collection of rumen fluids from live animals are urgently requested from the scientific community. Thus, in order to attenuate the dependence of laboratories on animal donors, this study compared the rumen inoculum collected at slaughter with the fermentation liquid from a rumen continuous fermenter and both rumen inoculum were used fresh or preserved (by refrigeration, chilling and freeze-drying). The results support the possibility of using continuous fermenters to generate inoculum for in vitro purposes, and short-term refrigeration is confirmed to be a valuable storage system to facilitate transfer inoculum from the collection sites. These findings should attenuate the need for laboratories’ frequent collections from animals while continuing research in ruminant nutrition.The utilization of animal donors of rumen fluid for laboratory experiments can raise ethical concerns, and alternatives to the collection of rumen fluids from live animals are urgently requested. The aim of this study was to compare the fresh rumen fluid (collected at slaughter, W) with that obtained from a continuous fermenter (RCF) and three methods of rumen fluid preservation (refrigeration, R, chilling, C, and freeze-drying, FD). The fermentability of different inoculum was evaluated by three in vitro tests (neutral detergent fiber (NDF) and crude protein (CP) degradability and gas production, NDFd, RDP and GP, respectively) using six feeds as substrates. Despite the two types of inoculum differed in terms of metabolites and microbiota concentration, the differences in vitro fermentability between the two liquids were less pronounced than expected (−15 and 20% for NDFd and GP when the liquid of fermenter was used and no differences for RDP). Within each in vitro test, the data obtained from rumen and from fermenter liquids were highly correlated for the six feeds, as well as between W and R (r: 0.837–0.985; p < 0.01). The low fermentative capacity was found for C and, particularly, FD for liquids. RCF could be used to generate inoculum for in vitro purposes and short-term refrigeration is a valuable practice to manage inoculum.

Characteristic of Biomass of Corn (Zea Mays Identata) Fermented by Lactobacillus Acidophilus and Bifidobacterium Brevis as Source of Natural Folic Acid

Nixtamalized yellow and white corn from type of horse dent (Zea mays var. identata) fermented by Lactic Acid Bacteria (LAB) has potential use as source of natural folic acid. Fermentation uses four (4) types of corn inoculum expressed as inoculums A, B, C and D, i.e: Inoculum A (nixtamalized white corn, sucrosse 10% w/w, skim milk 10% w/w using inoculum L. acidophilus 30% fermented 8 hours), inoculum B (nixtamalized white corn without sucrosse and skim milk using inoculum Bif. brevis 30% fermented 24 hours), Inoculum C (nixtamalized yellow corn, sucrosse 10% w/w, skim milk 10% w/w with inoculum L. acidophilus 30% fermented 16 hours), and inoculum D(nixtamalized yellow corn, sucrosse 10% w/w, skim milk 10% w/w with inoculum Bif. brevis 30% fermented 8 hours). Fermentation was done at inoculum concentrations 0, 10, 20, 30, and 40 % (v/w dissolved protein) and 37 °C for 24 hours. Result of experiment work showed that optimizations fermentation were reached by biomass B and biomass D at inoculum concentration 40 % with composition of folic acid 103.07 and 91.92 µg/mL, followed by particle sizes 987.4 and 762.8 nm, folic acid monomer with (MW) 443.70 and 442.96 (Da).

Uji Efektivitas Inokulum Fungi Mikoriza Arbuskula Terhadap Pertumbuhan Bibit Jati (Tectona Grandis Linn. F)

Arbuscular mycorrhizal fungi is a phylum of Glomeromycota. Arbuscular mycorrhizal fungi (AMF) propagule are spores, mycor-rhizal fungal hyphae and infected root fragments. The aims of this research were to analyze the effectivity of root inoculum of AMF to enhance teak (Tectona grandis Linn F.) seedling growth. The research was used complete randomized design (CRD)-split plot design. The main plot was root inoculum of AMF, sub plot is a media sterilization and media is not sterilized. The results showed that root inoculum of AMF and media effectively improved teak growth, especially in height, diameter, and shoot dry weight. Root inoculum of AMF is able to be used as the source of inoculum for the growth teak seedling. Fresh inoculum was found to be better than root inoculum stored at room temperature and root inoculum stored at refrigerator temperature (5°C). Storage of root inocu-lum at room temperature and refrigerator temperature (5°C) for two weeks decreased the effectiveness of inoculum. Type of mixed inoculum and inoculum of Acaulospora sp. root resulted in better growth compared with G. clarum root inoculum.

Assessing the stability of anaerobic co-digestion in the context of a WWTP with thermal pre-treatment of sewage sludge. Case study in Chile

In this study, beverage wastewater (BW) and extended aeration sewage sludge were assessed as co-substrates with both mixed sludge and thermally hydrolyzed sludge as substrates in an anaerobic codigestion (AcoD) process. The methodology is an integrated methodology that comprises a batch test (BMP) and semicontinuous reactor along with microbial diversity analysis. The results showed that in batch conditions, neither significant synergistic nor antagonistic effects were observed on the maximum potential (P) due to the cosubstrates presence. However, synergistic effects on a kinetic parameter (Rm) were observed when BW was used as cosubstrate. Process instability was observed in semi-continuous mode with cosubstrate BW, which was not predicted by the BMP test. As demonstrated in this study, the BMP approach is also not suitable for predicting continuous performance in real systems; however, it can be used to screen an array of substrates. In semi-continuous mode, one can expect to reach values between 50 and 60% of the biogas potential and 20–40% of the maximum production rate achieved in batch tests. The agreement between batch and semi-continuous results is also dependent on the type of inoculum used. The microbial diversity of the system was more influenced by the reactor stability than the presence of cosubstrates. To predict the performance (and stability) of real anaerobic digesters, dynamic models should be employed.

Effects of several inocula on the biochemical hydrogen potential of sludge-vinasse co-digestion

The influence of the inoculum on the Biochemical Hydrogen Potential test (BHP) was investigated. Thermophilic BHP from sludge-vinasses co-digestion (50:50) was studied employing three types of inocula: Acidogenic Inoculum, Sludge Inoculum and Thermal Sludge Inoculum. The maximum hydrogen yield was obtained with a sludge inoculum (177 mL H2/g VSadded). This yield was 21 and 36% higher than for acidogenic inoculum and thermal sludge inoculum, respectively. The results revealed that the choice of inoculum had significant impact on the hydrogen yield and the sludge inoculum is the most beneficial for BHP tests. The percentages between Eubacteria:Archaea increased from 59.2:40.8 to 92.0:9.0 during BHP tests using the sludge inoculum while it remained stablish in the others cases around 50:50. Furthermore, hydrogen production was accompanied by the generation of volatile fatty acids, mainly acetic, butyric and propionic acids. There were no differences in the rate of hydrogen production in any of the BHP.