Effect Of Different Inocula Research Articles

Effect of different inocula on the granulation process, reactor performance and biodiesel production of algal-bacterial granular sludge (ABGS) under low aeration conditions

The algal-bacterial granular sludge (ABGS) system is a prospective wastewater treatment technology, but few studies focused on the effects of different inoculum types on the establishment of the ABGS system under low aeration conditions (step-decrease superficial gas velocity from 1.4 to 0.5 cm/s). Results from this study indicated that compared with other inocula, the ABGS formed by co-inoculating aerobic granular sludge (AGS) and targeted algae (Chlorella) exhibited a shorter granulation period (shortened by 15 days), higher total nitrogen (89.4%) and PO43--P (95.0%) removal efficiencies, and a greater yield of fatty acid methyl esters (FAMEs) (9.04 mg/g MLSS). This was possibly attributed to that the functional bacteria (e.g. Thauera, Gemmobacter and Rhodobacter) in the inoculated AGS facilitated the ABGS granulation. The inoculated algae promoted their effective enrichment under illumination conditions and enhanced the production of extracellular polymeric substances, thus improving the stability of ABGS. The enriched algae were attached to the outer layer of the granules, which could provide sufficient oxygen for bacterial metabolism, revealing the inherent mechanisms for the good stability of ABGS under low aeration intensity. Overall, the rapid granulation of ABGS can be achieved by inoculating optimal inocula under low aeration conditions, which is convenient and economically feasible, and motivates the application of algal-bacterial consortia.

Exploring the roles of and interactions among microbes in dry co-digestion of food waste and pig manure using high-throughput 16S rRNA gene amplicon sequencing

BackgroundWith the increasing global population and increasing demand for food, the generation of food waste and animal manure increases. Anaerobic digestion is one of the best available technologies for food waste and pig manure management by producing methane-rich biogas. Dry co-digestion of food waste and pig manure can significantly reduce the reactor volume, capital cost, heating energy consumption and the cost of digestate liquid management. It is advantageous over mono-digestion of food waste or pig manure due to the balanced carbon/nitrogen ratio, high pH buffering capacity, and provision of trace elements. However, few studies have been carried out to study the roles of and interactions among microbes in dry anaerobic co-digestion systems. Therefore, this study aimed to assess the effects of different inocula (finished digestate and anaerobic sludge taken from wastewater treatment plants) and substrate compositions (food waste to pig manure ratios of 50:50 and 75:25 in terms of volatile solids) on the microbial community structure in food waste and pig manure dry co-digestion systems, and to examine the possible roles of the previously poorly described bacteria and the interactions among dry co-digestion-associated microbes.ResultsThe dry co-digestion experiment lasted for 120 days. The microbial profile during different anaerobic digestion stages was explored using high-throughput 16S rRNA gene amplicon sequencing. It was found that the inoculum factor was more significant in determining the microbial community structure than the substrate composition factor. Significant correlation was observed between the relative abundance of specific microbial taxa and digesters’ physicochemical parameters. Hydrogenotrophic methanogens dominated in dry co-digestion systems.ConclusionsThe possible roles of specific microbial taxa were explored by correlation analysis, which were consistent with the literature. Based on this, the anaerobic digestion-associated roles of 11 bacteria, which were previously poorly understood, were estimated here for the first time. The inoculum played a more important role in determining the microbial community structure than substrate composition in dry co-digestion systems. Hydrogenotrophic methanogenesis was a significant methane production pathway in dry co-digestion systems.

Toxoplasmic Infection-induced Injury in the Ileal Myenteric Plexus in Rats Depends on the Dose of Toxoplasma gondii Oocysts

Introduction The present study evaluated the effects of different inocula of Toxoplasma gondii oocysts on the ileal myenteric plexus in rats. Materials and Methods Male Wistar rats, 60 days old, were distributed into four groups: control group (CG; which received saline solution) and groups that were infected with 100 (TG100), 1000 (TG1000), and 5000 (TG5000) T. gondii oocysts. Thirty days after infection, the rats were sacrificed, and the ileum was collected to make whole-mount preparations that were subjected to immunofluorescence staining to observe the general neuronal population (HuC/D), nitrergic neurons (nNOS), and enteric glial cells (S100). Morphometric and quantitative analyses of myenteric neurons were performed. Results The infections with different T. gondii inocula did not cause neuronal or glial loss, but cause neuronal hypertrophy in general population and nitrergic subpopulation in infected groups. Conclusion: Changes in neuronal morphology were observed in the TG5000 group, including the presence of vacuoles, translocation of Hu protein to the nucleus, and dendritic distortions, suggesting functional alterations in these cells.

Effect of different inocula of Rotylenchulus reniformis and their management with botanicals on Sunflower

The results revealed that the plants inoculated with 10 and 100 nematodes (J4) were similar in growth as compared to check treatment. However, gradual loss in plant growth parameters was observed with increase in inoculum levels. This showed that Rotylenchulus reniformis was found pathogenic to the sunflower crop which adversely affected the growth. For the management of nematode five plants leaves namely neem, marigold, dhatura, oak, and lantana were evaluated for the nematicidal properties against R. reniformis. When plants extracts (S/8 &S/16 dilutions) were put around sunflower crop in pots, resulted an increase in shoot length, max. being in dhatura leaves extract. Similarly, a significant increase of shoot and root weights were also observed. However, maximum reduction of nematode population was noticed in neem and marigold leaf extracts.

Reactor performances and microbial communities of biogas reactors: effects of inoculum sources.

Anaerobic digestion is a very complex process that is mediated by various microorganisms, and the understanding of the microbial community assembly and its corresponding function is critical in order to better control the anaerobic process. The present study investigated the effect of different inocula on the microbial community assembly in biogas reactors treating cellulose with various inocula, and three parallel biogas reactors with the same inoculum were also operated in order to reveal the reproducibility of both microbial communities and functions of the biogas reactors. The results showed that the biogas production, volatile fatty acid (VFA) concentrations, and pH were different for the biogas reactors with different inocula, and different steady-state microbial community patterns were also obtained in different biogas reactors as reflected by Bray-Curtis similarity matrices and taxonomic classification. It indicated that inoculum played an important role in shaping the microbial communities of biogas reactor in the present study, and the microbial community assembly in biogas reactor did not follow the niche-based ecology theory. Furthermore, it was found that the microbial communities and reactor performances of parallel biogas reactors with the same inoculum were different, which could be explained by the neutral-based ecology theory and stochastic factors should played important roles in the microbial community assembly in the biogas reactors. The Bray-Curtis similarity matrices analysis suggested that inoculum affected more on the microbial community assembly compared to stochastic factors, since the samples with different inocula had lower similarity (10-20 %) compared to the samples from the parallel biogas reactors (30 %).

Effect of inoculum type and timing of application of Coniothyrium minitans on Sclerotinia sclerotiorum: influence on apothecial production

The effects of different inocula of the mycoparasite Coniothyrium minitans on carpogenic germination of sclerotia of Sclerotinia sclerotiorum at different times of year were assessed. A series of three glasshouse box bioassays was used to compare the effect of five spore‐suspension inocula of C. minitans, including three different isolates (Conio, IVT1 and Contans), with a standard maizemeal–perlite inoculum. Apothecial production, as well as viability and C. minitans infection of S. sclerotiorum sclerotia buried in treated soil, were assessed. Maizemeal–perlite inoculum at 107 CFU per cm3 soil reduced sclerotial germination and apothecial production in all three box bioassays, decreasing sclerotial recovery and viability in the second bioassay and increasing C. minitans infection of sclerotia in the first bioassay. Spore‐suspension inocula applied at a lower concentration (104 CFU per cm3 soil) were inconsistent in their effects on sclerotial germination in the three box bioassays. Temperature was an important factor influencing apothecial production. Sclerotial germination was delayed or inhibited when bioassays were made in the summer. High temperatures also inhibited infection of sclerotia by C. minitans. Coniothyrium minitans survived these high temperatures, however, and infected the sclerotia once the temperature decreased to a lower level. Inoculum level of C. minitans was an important factor in reducing apothecial production by sclerotia. The effects of temperature on both carpogenic germination of sclerotia and parasitism of sclerotia by C. minitans are discussed.

Peat-Based Toluene Biofiltration: A New Approach to the Control of Nutrients and pH

This paper describes an eighty days toluene vapour removal from air by a peat-based biofilter to study the effects of different inocula and nutrient supplies on the biofiltration efficiency. Four pure microbial strains were used for the inoculation of the biofilter matrix: i.e. Arthrobacter paraffineus, from the American Type Culture Collection (ATCC) and a further three aromatic hydrocarbons degraders selected from among those in private collections. The toluene inlet load was maintained at constant value throughout the trial. To improve toluene biofiltration, changes in the inoculation of the filter bed have been diversified. We have also investigated supply of nutrients by various aqueous solutions to humidify the filter packing material. Nutrients introduced by these solutions contained inorganic and organic nitrogen forms. To evaluate the influence of nutrient supplies, the operating parameter measurements have been monitored on an 80 day cycle. Parameters observed included the filter bed temperature, pressure drop and the toluene concentrations at both the entry and exit of the biofilter, the pH and physiological activities resulting from the various operational conditions.

Enhanced degradation of 3-nitropropanol by ruminal microorganisms.

Ruminal fluid was obtained over a 4-yr period from cattle on various diets and supplements to determine the effects of different inocula on the microbial degradation of 3-nitropropanol (NPOH), a toxic metabolite in certain Astragalus spp. (Leguminosae). Nitrite (NO2-) metabolism was also studied in vitro because rapid NO2- reduction is required for the overall detoxification of NPOH. Intra-ruminal supplements of sulfite were ineffective and produced toxic signs in treated animals. Ruminal fluid from cattle on fresh pasture diets enhanced the in vitro metabolism of NO2-, but rates of NPOH disappearance were not significantly affected. Rates of NPOH degradation increased when orchardgrass pasturage was supplemented with molasses. Enhancement of NPOH degradation was achieved with supplements of nitroethane given intra-ruminally at 6.5 or 10 mg/kg body weight. The effect of nitroethane on NO2- reduction was not always observed, but the NO2- rates of metabolism always exceeded those of NPOH. The rate of NPOH degradation also increased when nitroethane was added to a molasses supplement. However, the volatility of nitroethane under field conditions prompted a search for a more stable inducer and the sodium salt of nitroethane was subsequently evaluated. The salt of nitroethane, given intra-ruminally at 20 mg nitroethane/kg body weight, resulted in the highest rate of NPOH degradation; this was similar to that reported for 3-nitropropionic acid, a nitroalkane that is much less toxic to ruminants than NPOH.

Effect of atmosphere of incubation and inoculum size on the susceptibility of Eikenella corrodens.

The effect of atmosphere of incubation on the susceptibility of Eikenella corrodens to 13 antimicrobial agents was determined. Clindamycin, cefoxitin, cefotaxime, cefoperazone, moxalactam, meziocillin and piperacillin were more active in a 5% CO2 than in an anaerobic atmosphere. The activity of penicillin G, cefamandole, cefadroxil, ticarcillin, bacampicillin and N-formimidoyl thienamycin was not affected by environment. The effect of different inocula (103, 105, 108 and 109 cfu/ml) on the susceptibility of Eik. corrodens to penicillin G, clindamycin and cefoperazone was also tested. Penicillin G and clindamycin were equally active against all inoculum sizes, while cefoperazone was less active at the higher inocula.