Biohydrogen production from diary processing wastewater by anaerobic biofilm reactors

Fermentative hydrogen production was studied in packed bed batch reactors to assess the influence of environmental factors over yield hydrogen production from dairy wastewater. Dried stems of Opuntia imbricata were used as substratum adding a pretreated mixed culture for biofilm formation. Experimental results showed that, yield hydrogen production was significantly affected by initial COD concentration, temperature and dairy wastewater pH. Maximum yield obtained was 12.73 mM H2/g CODc when initial COD concentration was 21.1 g COD, dairy wastewater pH with no adjustment (11.32) and room temperature of 16 ± 3°C. Methane production was completely inhibit at an initial pH of 4 at all temperature studied (final pH 4.06), meanwhile, with an initial pH of 11.32, with exception for 16°C, methanogenic activity was not completely inhibit when final pH was over 5, showing an increase in methane production of 0.35 to 0.75 g CH4/l for 35 to 55°C.Key words: Biofilm, dairy wastewater, hydrogen, Opuntia imbricat

Yeasts associated with the production of distilled alcoholic beverages

Distilled alcoholic beverages are produced firstly by fermenting sugars emanating from cereal starches (in the case of whiskies), sucrose-rich plants (in the case of rums), fructooligosaccharide-rich plants (in the case of tequila) or from fruits (in the case of brandies). Traditionally, such fermentations were conducted in a spontaneous fashion, relying on indigenous microbiota, including wild yeasts. In modern practices, selected strains of Saccharomyces cerevisiae are employed to produce high levels of ethanol together with numerous secondary metabolites (eg. higher alcohols, esters, carbonyls etc.) which greatly influence the final flavour and aroma characteristics of spirits following distillation of the fermented wash. Therefore, distillers, like winemakers, must carefully choose their yeast strain which will be very important in providing the alcohol content and the sensory profiles of spirit beverages. This Chapter discusses yeast and fermentation aspects associated with the production of selected distilled spirits and highlights similarities and differences with the production of wine

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AimThe SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery.MethodsThis was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin.ResultsOverall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P ConclusionOne in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease