Trends in the biomanufacture of polyhydroxyalkanoates with focus on downstream processing.

The aim of the current review is to analyze trends in development of an efficient technology for polyhydroxyalkanoate (PHA) biomanufacture highlighting the up-to-date progress on PHA biosynthesis and focusing on the downstream processing. Three main production pathways were identified: through microbial, enzymic, or plant routes. Microbial fermentation processes were predominant, with a wide range of microorganisms, starting materials and culture conditions reported. Largely, two schemes for recovering PHAs from the reaction medium post fermentation were identified: dissolving biomass to separate PHAs granules with strong oxidants, and extracting PHAs directly from the biomass using suitable solvents. For the valuable industrial scale biosynthesis of PHA several technological elements need to be applied such as robust whole-cell microbial catalyst with its optimal culturing conditions, suitable carbon source, proper mode of process operation, as well as economical and ecological purification methods.

Enhancement of methane production from co-digestion of chicken manure with agricultural wastes.

The potential for methane production from semi-solid chicken manure (CM) and mixture of agricultural wastes (AWS) in a co-digestion process has been experimentally evaluated at thermophilic and mesophilic temperatures. To the best of author(')s knowledge, it is the first time that CM is co-digested with mixture of AWS consisting of coconut waste, cassava waste, and coffee grounds. Two types of anaerobic digestion processes (AD process) were used, process 1 (P1) using fresh CM (FCM) and process 2 (P2) using treated CM (TCM), ammonia stripped CM, were conducted. Methane production in P1 was increased by 93% and 50% compared to control (no AWS added) with maximum methane production of 502 and 506 mL g(-1)VS obtained at 55°C and 35°C, respectively. Additionally, 42% increase in methane production was observed with maximum volume of 695 mL g(-1)VS comparing P2 test with P2 control under 55°C. Ammonia accumulation was reduced by 39% and 32% in P1 and P2 tests.

Emotional, physical, and sexual abuse in fibromyalgia syndrome: a systematic review with meta-analysis.

OBJECTIVE: To systematically assess the potential association of fibromyalgia syndrome (FMS) with emotional, physical, and sexual abuse. METHODS: The databases EMBase, Google Scholar, Medline, and PsycINFO (through April 2010) and the reference sections of original studies were searched for eligible studies. Eligible studies were cohort or case--control studies that assessed at least one type of emotional, physical, or sexual abuse in childhood or adulthood in patients with FMS and in controls. Two authors independently extracted descriptive, quality, and outcome data from included studies. Methodologic quality was assessed by the Newcastle-Ottawa Quality Assessment Scale. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were pooled across studies by using the random-effects model. Heterogeneity was assessed by I(2) statistics. RESULTS: The search identified 18 eligible case-control studies with 13,095 subjects. There were significant associations between FMS and self-reported physical abuse in childhood (OR 2.49 [95% CI 1.81-3.42], I(2) = 0%; 9 studies) and adulthood (OR 3.07 [95% CI 1.01-9.39], I(2) = 79%; 3 studies), and sexual abuse in childhood (OR 1.94 [95% CI 1.36-2.75], I(2) = 20%; 10 studies) and adulthood (OR 2.24 [95% CI 1.07-4.70], I(2) = 64%; 4 studies). Study quality was mostly poor. Low study quality was associated with higher effect sizes for sexual abuse in childhood, but not with other effect sizes. CONCLUSION: The association of FMS with physical and sexual abuse could be confirmed, but is confounded by study quality.

Improved methane fermentation of chicken manure via ammonia removal by biogas recycle.

This study demonstrates methane fermentation that was carried out along with ammonia striping to avoid ammonia accumulation that significantly inhibited methane production. Ammonia was successfully removed by means of recycling of biogas followed by gas washing in sulfuric acid to capture ammonia, when chicken manure was anaerobically digested for 4 days at 55 degrees C and at an initial pH of 8-9. By using this method, 80% of total nitrogen in chicken manure was converted to ammonia and 82% of the produced ammonia was removed. A bench scale reactor equipped with an ammonia-stripping unit for methane production from chicken manure was developed and operated in repeated batch mode. At an initial pH of 8 and at 55 degrees C, 195 and 157 ml g-VS(-1) of methane was successfully produced from the treated chicken manure and the mixture of treated chicken manure and raw chicken manure in the ratio of 1:1, respectively. In this method, ammonia concentration was maintained at a level lower than 2g-N kg-wet sludge(-1) in the reactor.

Production of L(+) lactic acid using Lactobacillus casei from whey

The aim of this work was to study the fermentation of whey for the production of L(+) lactic acid using Lactobacillus casei. The effect of different process parameters such as pH of the medium, temperature, inoculum size, age of inoculum, agitation and incubation time was monitored to enhance the lactose conversion in whey to L(+) lactic acid. Fermentations were performed without any pH control. The optimization of the fermentation conditions resulted in significant decrease in fermentation time, besides increase in lactose conversion to lactic acid. The optimized process conditions resulted in high lactose conversion (95.62 percent) to L(+) lactic acid production (33.73 g/L) after an incubation period of 36 h.

Processing of food wastes.

Every year almost 45 billion kg of fresh vegetables, fruits, milk, and grain products is lost to waste in the United States. According to the EPA, the disposal of this costs approximately $1 billion. In the United Kingdom, 20 million ton of food waste is produced annually. Every tonne of food waste means 4.5 ton of CO(2) emissions. The food wastes are generated largely by the fruit-and-vegetable/olive oil, fermentation, dairy, meat, and seafood industries. The aim of this chapter is to emphasize existing trends in the food waste processing technologies during the last 15 years. The chapter consists of three major parts, which distinguish recovery of added-value products (the upgrading concept), the food waste treatment technologies as well as the food chain management for sustainable food system development. The aim of the final part is to summarize recent research on user-oriented innovation in the food sector, emphasizing on circular structure of a sustainable economy.

Use of immobilised biocatalysts in the processing of cheese whey.

Food processing industry operations need to comply with increasingly more stringent environmental regulations related to the disposal or utilisation of by-products and wastes. These include growing restrictions on land spraying with agro-industrial wastes, and on disposal within landfill operations, and the requirements to produce end products that are stabilised and hygienic. Much of the material generated as wastes by the dairy processing industries contains components that could be utilised as substrates and nutrients in a variety of microbial/enzymatic processes, to give rise to added-value products. A good example of a waste that has received considerable attention as a source of added-value products is cheese whey. The carbohydrate reservoir of lactose (4-5%) in whey and the presence of other essential nutrients make it a good natural medium for the growth of microorganisms and a potential substrate for bioprocessing through microbial fermentation. Immobilised cell and enzyme technology has also been applied to whey bioconversion processes to improve the economics of such processes. This review focuses upon the elaboration of a range of immobilisation techniques that have been applied to produce valuable whey-based products. A comprehensive literature survey is also provided to illustrate numerous immobilisation procedures with particular emphasis upon lactose hydrolysis, and ethanol and lactic acid production using immobilised biocatalysts.

Monitoring population dynamics of the thermophilic Bacillus licheniformis CCMI 1034 in batch and continuous cultures using multi-parameter flow cytometry.

Multi-parameter flow cytometry was used to monitor the population dynamics of Bacillus licheniformis continuous cultivations and the physiological responses to a starvation period and a glucose pulse. Using a mixture of two specific fluorescent stains, DiOC6(3) (3,3'-dihexylocarbocyanine iodide), and PI (propidium iodide), flow cytometric analysis revealed cell physiological heterogeneity. Four sub-populations of cells could be easily identified based on their differential fluorescent staining, these correspond to healthy cells (A) stained with DiOC6(3); cells or spores with a depolarised cytoplasmic membrane (B), no staining; cells with a permeabilised depolarised cytoplasmic membrane (C), stained with PI; and permeablised cells with a disrupted cytoplasmic membrane 'ghost cells' (D), stained with both DiOC6(3) and PI. Transmission electron micrographs of cells starved of energy showed different cell lysis process stages, highlighting 'ghost cells' which were associated with the double stained sub-population. It was shown, at the individual cell level, that there was a progressive inherent fluctuation in physiological heterogeneity in response to changing environmental conditions. All four sub-populations were shown to be present during glucose-limited continuous cultures, revealing a higher physiological stress level when compared with a glucose pulsed batch. A starvation period (batch without additional nutrients) increased the number of cells in certain sub-populations (cells with depolarised cytoplasmic membranes and cells with permeabilised depolarised cytoplasmic membranes), indicating that such stress may be caused by glucose limitation. Such information could be used to enhance process efficiency.