Efect of the volatile fatty acids on phosphate uptake parameters by pure cultures of Acinetobacter

Production of polyhydroxyalkanoates (PHAs) as bio-alternative to petroleum-based plastics is an important field in the biorefinery to move forward in the development of the circular economy. PHAs are bioplastics stored inside microbial cells as carbon reservoirs and can be produced from a broad range of renewable resources such as waste streams. One important waste stream is food waste that can be converted into volatile fatty acids (VFAs) by anaerobic digestion. The produced effluent from food waste is not only rich in VFAs but also, other nutrients such as nitrogen and phosphorus that can be used by the microorganisms to produce PHAs. The aim of this research is to convert VFAs produced from food waste into PHAs, in which two approaches have been studied. The first approach was to use microbial mixed cultures (MMCs) while the second used microbial pure cultures. The MMCs were enriched in sequencing batch bioreactor cultivations, where nitrogen and carbon starvation were combined to enhance the selection phase. PHA accumulation of the selected cultures was studied in nitrogen-limited fed-batch cultivations. The second approach studied five different PHA producing bacteria: Cupriavidus necator, Burkholderia cepacea, Bacillus megaterium, Bacillus cereus and Bacillus cereus. To select the most promising bacteria, synthetic medium with the same VFAs composition as in MMCs study was used for pre-screening experiments. Both, pure and mixed culture studies, resulted in the production of PHAs containing (R)-3-hydroxybutyrate, (R)-3-hydroxyvalerate and (R)-3-hydroxyhexanoate as monomers and VFAs were consumed with a high rate by the microorganisms.

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To Remove Phosphate from Municipal Wastewater with Insufficient Volatile Fatty Acids

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.356-360.1769 ◽

2011 ◽

Vol 356-360 ◽

pp. 1769-1772

Author(s):

Gong Fa Chang ◽

Feng Zhang ◽

Chang Qing Liu ◽

Bo Zhang ◽

Xue Jun Bi

Keyword(s):

Fatty Acids ◽

Carbon Source ◽

Volatile Fatty Acids ◽

Municipal Wastewater ◽

Phosphate Uptake ◽

Plug Flow ◽

Phosphate Concentration ◽

Phosphate Removal ◽

Flow Reactors ◽

Phosphate Release

Tow plug flow reactors were operated with municipal wastewater according to reversed A2/O process. The only difference was in sludge return ratio. Despite that more VFAs were consumed by denitrification, phosphate removal was enhanced rather than impaired by a higher sludge return ratio of 300%. It seems that higher phosphate removal can be achieved even more nitrate was reduced which means more carbon source consumption. This is contradictory with the well accepted enhanced biological phosphate removal (EBPR) theory, which regards sufficient volatile fatty acids in the wastewater as the indispensable premise. With less phosphate was released in the anaerobic zones, the final phosphate concentration in the effluent was lower when higher sludge return ratio was applied. The results indicated that neither carbon source nor phosphate release can directly determine phosphate uptake ability.

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Role of Volatile Fatty Acids in Development of the Cecal Microflora in Broiler Chickens during Growth

Applied and Environmental Microbiology ◽

10.1128/aem.66.6.2536-2540.2000 ◽

2000 ◽

Vol 66 (6) ◽

pp. 2536-2540 ◽

Cited By ~ 199

Author(s):

Paul W. J. J. van der Wielen ◽

Steef Biesterveld ◽

Servé Notermans ◽

Harm Hofstra ◽

Bert A. P. Urlings ◽

...

Keyword(s):

Fatty Acids ◽

Broiler Chickens ◽

Volatile Fatty Acids ◽

Bacterial Populations ◽

Large Numbers ◽

Pure Cultures ◽

High Concentrations ◽

Cecal Microflora

ABSTRACT It is known that volatile fatty acids can inhibit growth of species of the family Enterobacteriaceae in vitro. However, whether these volatile fatty acids affect bacterial populations in the ceca of chickens is unknown. Therefore, a study was conducted to investigate if changes in volatile fatty acids in ceca of broiler chickens during growth affect bacterial populations. Results showed that members of theEnterobacteriaceae and enterococci are present in large numbers in 3-day-old broilers and start to decrease when broilers grow older. Lactobacilli are present in large numbers as well in 3-day-old broilers, but they remain stable during the growth of broilers. Acetate, butyrate, and propionate increase from undetectable levels in 1-day-old broilers to high concentrations in 15-day-old broilers, after which they stabilize. Significant negative correlations could be calculated between numbers of Enterobacteriaceae and concentrations of undissociated acetate, propionate, and butyrate. Furthermore, pure cultures of Enterobacteriaceae isolated from the ceca were grown in the presence of volatile fatty acids. Growth rates and maximal optical density decreased when these strains grew in the presence of increasing volatile fatty acid concentrations. It is concluded that volatile fatty acids are responsible for the reduction in numbers of Enterobacteriaceae in the ceca of broiler chickens during growth.

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Unravelling a microbial synergy to boost caproate production via carboxylates chain elongation with ethanol

HKIE Transactions ◽

10.33430/v26n2thie-2018-0041 ◽

2019 ◽

Vol 26 (2) ◽

pp. 63-71

Author(s):

Ling Leng ◽

Ying Wang ◽

Peixian Yang ◽

Takashi Narihiro ◽

Masaru Konishi Nobu ◽

...

Keyword(s):

Fatty Acids ◽

Volatile Fatty Acids ◽

Microbial Consortia ◽

Chain Elongation ◽

Desulfovibrio Vulgaris ◽

Rrna Gene ◽

Selective Enrichment ◽

Microbial Network ◽

Cost Efficient ◽

Rrna Gene Sequencing

Chain elongation of volatile fatty acids for medium chain fatty acids production (e.g. caproate) is an attractive approach to treat wastewater anaerobically and recover resource simultaneously. Undefined microbial consortia can be tailored to achieve chain elongation process with selective enrichment from anaerobic digestion sludge, which has advantages over pure culture approach for cost-efficient application. Whilst the metabolic pathway of the dominant caproate producer, Clostridium kluyveri, has been annotated, the role of other coexisting abundant microbiomes remained unclear. To this end, an ethanol-acetate fermentation inoculated with fresh digestion sludge at optimal conditions was conducted. Also, physiological study, thermodynamics and 16 S rRNA gene sequencing to elucidate the biological process by linking the system performance and dominant microbiomes were integrated. Results revealed a possible synergistic network in which C. kluyveri and three co-dominant species, Desulfovibrio vulgaris, Fusobacterium varium and Acetoanaerobium sticklandii coexisted. D. vulgaris and A. sticklandii (F. varium) were likely to boost the carboxylates chain elongation by stimulating ethanol oxidation and butyrate production through a syntrophic partnership with hydrogen (H2) serving as an electron messenger. This study unveils a synergistic microbial network to boost caproate production in mixed culture carboxylates chain elongation.

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МЕТАБОЛИТЫ ПРОБИОТИЧЕСКИХ БАКТЕРИЙ ОТВЕЧАЮТ ЗА ЭФФЕКТИВНОСТЬ ДЕЙСТВИЯ ПРОБИОТИКА "ПРОФОРТ®"

10.33845/0033-3239-2019-68-9-10-45-47 ◽

2019 ◽

Keyword(s):

Fatty Acids ◽

Volatile Fatty Acids ◽

Broiler Chicks ◽

Bacillus Sp

МЕЛИКИДИ В.Х., ТЮРИНА Д.Г., СЕЛИВАНОВ Д.Г., НОВИКОВА Н.И. ООО «БИОТРОФ», Санкт-Петербург Аннотация: Приведены данные исследования методом газожидкостной хроматомасс-спектрометрии метаболитов, синтезируемых пробиотическими бактериями, входящими в состав кормовой добавки «Профорт®». Проведен опыт в условиях интенсивного промышленного птицеводства по применению кормовой добавки «Профорт®» (50 тыс. голов бройлеров в группе). Среди метаболитов пробиотических штаммов Enterococcus sp. и Bacillus sp. обнаружены такие полезные вещества, как молочная кислота, уксусная, пропионовая и другие короткоцепочечные (летучие) жирные кислоты, активные пептиды. Результаты зоотехнического опыта показали, что при скармливании бройлерам пробиотика «Профорт®» (500 г/т) живая масса при убое в 40 дней была выше контроля на 6,9%, конверсия корма улучшилась на 3,0%, а европейский индекс продуктивности бройлеров - на 5,69%. Ключевые слова: ПРОБИОТИКИ, МЕТАБОЛИТЫ, ЛЕТУЧИЕ ЖИРНЫЕ КИСЛОТЫ, ЦЫПЛЯТА-БРОЙЛЕРЫ,ПРОДУКТИВНОСТЬ, PROBIOTICS, METABOLITES, VOLATILE FATTY ACIDS, BROILER CHICKS,PRODUCTIVITY

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