Effect of cow diet on the ruminal microflora and its in vitro fatty acid production

The objective of this study was to investigate the effects of donor’s cow diet (hay or maize silage plus concentrates) on ruminal bacteria count, flora diversity and fatty acids profile (FA) of ruminal fluid and in vitro biohydrogenation (BH) of C18:2. Two dry cows fitted with a ruminal canula were used in a 2x2 design. Each period included three weeks of diet adaptation and two weeks of sampling. The cows were fed twice daily either a diet (H) composed of grass (38%) and alfalfa hay (62%) or an acidogenic diet (A) composed of maize silage (38%), wheat (57%) and soybean (5%) meal. Ruminal fluid was sampled and centrifugated (150g, 5min., 39°C). The ruminal fluid (80mL) was mixed with 80mL of buffer, a fermentative substrate and grape seed oil as source of C18:2 before being incubated during 6 hours at 39°C in anaerobic and dark conditions. Biodiversity was estimated by the Simpson index modified by Haegeman et al.1 after SSCP analysis, and FA were analysed by GLC. Bacteria counting was realised according to Oblinger and Koburger2 (1975). Total and cellulolytic bacteria contents were higher in inoculum A than in inoculum H (9.3.109 vs. 2.4.108/mL for total bacteria and 2.4.108 vs. 1.6.107/mL for cellulolytic bacteria). No difference in the biodiversity of the inoculums was noticed according to the cow or the diet, but diversity during period 1 tended to differ (P=0.09) from period 2, suggesting a time variation of flora biodiversity. Before incubation, the ruminal fluid from the cow receiving diet A contained significantly (P<0.01) more C18:2, trans-10 and trans-11 C18:1, and odd-chain FA than inoculum from the cow receiving diet H. After incubation, inoculum A resulted in a significantly (P<0.01) greater BH of C18:2 than inoculum H, and produced more trans-10C18:1, trans-11C18:1 and odd-chain FA (P<0.01) Trans-10 and odd-chain FA are known to be increased by a high concentrate diet, which explains that inoculum A was richer in these FA than inoculum H. The ruminal flora selected in vivo by diet A continued the production of these FA in vitro. The greater content of trans-11C18:1 and of C18:2 in the inoculum A could be explained by the greater content in C18:2 of the diet A. During incubation with added C18:2, inoculum A continued to produce more trans-11 along with a higher C18:2 BH than inoculum H, which could be due to the higher concentration of cellulolytic bacteria in the inoculum A

Pengaruh Berbagai Jenis Tanaman Inang dan Beberapa Jenis Sumber Inokulum terhadap Infektivitas dan Efektivitas Mikoriza

. This research aims to study the types of host plants and source of inoculum is best in the manufacture of mycorrhizal biofertilizer. The study was conducted at the home screen Unsyiah Faculty of Agriculture, Soil Biology Laboratory at USU College of Agriculture and Soil Chemistry Laboratory at the Faculty of Agriculture Unsyiah since July 2011 to November 2011. This research used randomized completely block design (RCBD) factorial with two factors and three replications. Factors studied are several types of host plants and some types of sources of inoculum. Variety of host factors consist: kudzu, soybean, and corn and factors source of inoculum consisted of: spore origin rhizosfer kudju, rhizosfer spores from soybean, and spores rhizosfer origin of maize. Variables observed in this study is the degree of mycorrhizal infection, plant P uptake. From the research results obtained can be concluded that there is interaction between host plant species with the type of source of inoculum of mycorrhizal infectivity and effectiveness. The best treatment of the parameters of the degree of mycorrhizal infection (infectivity of mycorrhizal) and plant P uptake (mycorrhizal effectiveness) is a combination of host plant kudzu to the source of spore inoculum origin rhizosfer kudzu

Anaerobic digestate as substrate for microalgae culture: the role of ammonium concentration on the microalgae productivity

In spite of the increasing interest received by microalgae as potential alternatives for biofuel production, the technology is still not industrially viable. The utilization of digestate as carbon and nutrients source can enhance microalgal growth reducing costs and environmental impacts. This work assesses microalgal growth utilizing the liquid phase of anaerobic digestate effluent as substrate. The effect of inoculum/substrate ratio on microalgal growth was studied in a laboratory batch experiment conduced in 0.5 L flasks. Results suggested that digestate may be an effective substrate for microalgal growth promoting biomass production up to 2.6 gTSS/L. Microalgal growth rate was negatively affected by a self-shading phenomenon, while biomass production was positively correlated with the inoculum and substrate concentrations. Thus, the increasing of both digestate and microalgal initial concentration may reduce the initial growth rate (µ from 0.9 to 0.04 d-1) but significantly enhances biomass production (from 0.1 to 2.6 gTSS/L).Peer ReviewedPostprint (published version

Sumber Inokulum, Respons Varietas, Dan Efektivitas Fungisida Terhadap Penyakit Karat Putih Pada Tanaman Kris

. Suhardi. 2009. Inoculum Source, Variety Response, and Fungicide Efficacy to Rust Disease ofChrysanthemum. Studies to evaluate the role of cutting as an inoculum source, variety resistance, and fungicideapplication interval were done at Indonesian Ornamental Crops Research Institute. Survey of cutting health wascarried out at farmer's fields as seed producer on July 2002. A study under plastichouse to evaluate the response ofsome cultivars and determine the efficacy of fungicide applications was carried out from July-September 2002. Theresults indicated that cuttings were the inoculum source of rust on chrysanthemum. On individual plant, both underplastic and glasshouse, the development of white rust was suppressed. Phuma White cultivar relatively more resistantthan cv. Reagent Ungu and cv. Town Talk. Benomyl (benzimidazole) fungicide was not effective yet in controllingchrysanthemum white rust (P. horiana)

Microbial ecosystem constructed in water for successful organic hydroponics

Conventional hydroponics systems generally use only chemical fertilisers, not organic ones, since there are no microbial ecosystems present in such systems to mineralise organic compounds to inorganic nutrients. Addition of organic compounds to the hydroponic solution generally has phytotoxic effects and causes poor plant growth. We developed a novel hydroponic culture method using organic fertiliser. A microbial ecosystem was constructed in hydroponic solution by regulating the amounts of organic fertiliser and soil, with moderate aeration. The microbial ecosystem mineralised organic nitrogen to nitrate-nitrogen via ammonification and nitrification. A 97.6% efficiency of nitrate-nitrogen generation from the organic nitrogen in the organic fertiliser was achieved. The culture solution containing the microbial ecosystem was usable as a hydroponic solution. Vegetable plants grew well in our organic hydroponics system under continuous addition of organic fertiliser, and the yield and quality approximated those of vegetables grown by conventional hydroponics

Native and invasive inoculation sources modify fungal community assembly and biomass production of a chaparral shrub

Feedbacks between plants and surrounding soil microbes can contribute to the establishment and persistence of invasive annual grasses as well as limit the success of restoration efforts. In this study, we aim to understand how three sources of soil inocula – native, invasive (from under Bromus diandrus) and sterile – affect the growth response and fungal community composition in the roots of a chaparral shrub, Adenostoma fasciculatum. We grew A. fasciculatum from seed in a greenhouse with each inoculum source and harvested at six months. We measured above- and below-ground biomass, arbuscular mycorrhizal fungal (AMF) colonization and conducted targeted-amplicon sequencing of the 18S and ITS2 loci to characterize AMF and general fungal community composition, respectively. Native inoculum resulted in roots with richer communities of some groups of AMF and non-AMF symbionts, when compared to roots grown with invasive or sterile inoculum. Seedlings grown with invasive and native inoculum did not have different growth responses, but both produced more biomass than a sterile control. These findings suggest that inoculation with soil from native species can increase the diversity of multiple groups of fungal symbionts and inoculation with live soil (invasive or native) can increase seedling biomass. Moreover, future work would benefit from assessing if a more diverse community of fungal symbionts increases seedling survival when planted in field restoration sites

Assessment of anaerobic co-digestion of food waste and wastewater solids for sustainable waste management in Yosemite National Park, USA

The growing need for sustainable municipal solid waste treatment and energy production has driven the development of new waste management methods like co-digestion. Anaerobic co-digestion of food waste (FW) and wastewater solids (WWS) has been implemented at a few wastewater treatments plants to efficiently treat organic wastes and produce methane-rich biogas as an energy source. Yosemite National Park has an opportunity to design a new co-digestion facility with an upcoming upgrade to their local wastewater treatment plant in El Portal, California. The Park annually produces approximately 5 million tons of primary WWS and 1 million tons of FW waste, with a volatile solid ratio of 70:30 FW to WWS, or 70% FW. Diverted FW is currently sent to the Mariposa County landfill’s compost facility. To measure the possible increase in biogas production associated with FW addition to WWS, a biochemical methane potential (BMP) test was done over 35 days under mesophilic conditions with treatment mixing ratios ranging from 0% to 100% FW on a volatile solids basis. Calculated annual methane production increased 3.25 times from 0% FW scenario (WWS only) versus a 70% FW scenario, translating to a potential increase in methane production at the wastewater treatment plant of 28,000 to 91,000 m3/yr. Results showed that if the wastewater treatment plant also implemented combined heat and power to combust the increased biogas from 70% FW co-digestion, potentially 920,000 kWh/yr could be produced to cover all electricity and heating needs. This research demonstrates that Yosemite National Park could combine FW and WWS to sustainably manage their organic waste in line with their Zero Landfill Initiative, as well as produce enough energy to fully power the El Portal wastewater treatment plant

Standardization of activated sludge for biodegradation tests

Activated sludges are an inoculum source commonly used in biodegradation studies, as wastewater treatment facilities constitute an entry point to the environment for many chemicals. In this paper, the main issues relating to the use of activated sludge in biodegradability tests are presented. Special attention is also devoted to discussing the factors affecting both the activity of the microbial communities and the test results. After a short survey of the state of the art of microbiology of activated sludge, the paper focuses on the methods used to reduce the variations in the diversity, quality and quantity of these communities. Finally, use of surrogates as reference materials in biodegradability tests is discussed