Ecotoxicological assessment of biomass-derived furan platform chemicals using aquatic and terrestrial bioassays.

An environmental toxicological assessment of fourteen furanic compounds serving as valuable building blocks produced from biomass was performed. The molecules selected included well studied compounds serving as control examples to compare the toxicity exerted against a variety of highly novel furans which have been additionally targeted as potential or current alternatives to biofuels, building blocks and polymer monomers. The impact of the furan platform chemicals targeted on widely applied ecotoxicity model organisms was determined employing the marine bioluminescent bacterium Aliivibrio fischeri and the freshwater green microalgae Raphidocelis subcapitata, while their ecotoxicity effects on plants were assessed using dicotyledonous plants Sinapis alba and Lepidium sativum. Regarding the specific endpoints evaluated, the furans tested were slightly toxic or practically nontoxic for A. fischeri following 5 and 15 min of exposure. Moreover, most of the building blocks did not affect the growth of L. sativum and S. alba at 150 mg L-1 for 72 h of exposure. Specifically, 9 and 11 out of the 14 furan platform chemicals tested were non-effective or stimulant for L. sativum and S. alba respectively. Given that furans comprise common inhibitors in biorefinery fermentations, the growth inhibition of the specific building blocks was studied using the industrial workhorse yeast Saccharomyces cerevisiae, demonstrating insignificant inhibition on eukaryotic cell growth following 6, 12 and 16 h of exposure at a concentration of 500 mg L-1. The study provides baseline information to unravel the ecotoxic effects and to confirm the green aspects of a range of versatile biobased platform molecules.

Exploring vaccination coverage and attitudes of health care workers towards influenza vaccine in Cyprus.

Seasonal influenza is a major public health problem. Nosocomial influenza is particularly concerning as it may affect patients at high risk for complications. Unvaccinated health care workers (HCWs) are an important source of nosocomial influenza and therefore a priority target group for vaccination. Despite the fact that some European countries have high coverage rates such as UK (76.8% in season 2020/21), others continue to have low coverage rates for influenza vaccines. This study aims to estimate vaccination coverage in HCWs in Cyprus, an island country located in the Eastern Mediterranean region and describe their attitudes towards influenza vaccination. METHODS: This is a questionnaire based, nation-wide study assessing flu vaccination coverage in 2019-2020 and attitudes related to vaccination acceptance, of 962 HCWs in both public and private health care facilities. Multivariable logistic regression was used to investigate factors associated with flu vaccination status. RESULTS: Flu vaccination coverage was estimated as 31.8%. The top two reasons for getting vaccinated were to protect their family (81.4%) and themselves (77.4%). The top two reasons for not getting immunised, besides "no particular reason" (25.7%), included disbelief for vaccine effectiveness (21.5%) and safety (29.3%). The regression model showed that doctors compared to nurses had 10 times the odds of being vaccinated. Other factors positively associated with flu vaccination were encouragement by the supervisor, having sufficient knowledge on flu and flu vaccination and easy access to vaccination. A percentage of 54.8% of participants stated that COVID-19 pandemic strongly or somewhat influenced their decision to get vaccinated. CONCLUSION: Flu vaccination coverage in HCWs in Cyprus is rather low, similar to some other European countries. Barriers and facilitators in this study can be considered in strategies to increase flu vaccination uptake. Such questionnaire-based surveys should be repeated in order to evaluate effectiveness of targeted vaccination campaigns.

Ultrasound-assisted dilute acid hydrolysis for production of essential oils, pectin and bacterial cellulose via a citrus processing waste biorefinery.

An orange peel waste biorefinery was developed employing a design of experiments approach to optimize the ultrasound-assisted dilute acid hydrolysis process applied for production of useful commodities. Central composite design-based response surface methodology was used to approximate the combined effects of process parameters in simultaneous production of essential oils, pectin and a sugar-rich hydrolyzate. Application of a desirability function determined the optimal conditions required for maximal production efficiency of essential oils, pectin and sugars as 5.75% solid loading, 1.21% acid concentration and 34.2 min duration. Maximum production yields of 0.12% w/w essential oils, 45% w/w pectin and 40% w/w sugars were achieved under optimized conditions in lab- and pilot-scale facilities. The hydrolyzate formed was applied in bacterial cellulose fermentations producing 5.82 g biopolymer per 100 g waste. Design of experiments was efficient for process analysis and optimization providing a systems platform for the study of biomass-based biorefineries.

A biorefinery for conversion of citrus peel waste into essential oils, pectin, fertilizer and succinic acid via different fermentation strategies.

A process for the valorization of citrus peel waste (CPW) has been developed aiming to produce succinic acid and a series of added-value products through the biorefinery platform. CPW was subject to physicochemical and biological treatment to isolate essential oils (0.43%) and pectin (30.53%) as extractable products, pretreating the material for subsequent production of succinic acid that enabled application of remaining biorefinery residues (BR) as fertilizer substitute. Cellulose, hemicellulose and lignin contents of CPW accounted for 22.45%, 8.05% and 0.66% respectively, while acid hydrolysis reduced hemicellulose by 3.42% in BR. Moreover, essential oils extracted from CPW included 17 compounds, among which D-limonene reached 96.7%. The hydrolyzate generated was fermented for succinic acid production using Actinobacillus succinogenes. Different batch experiments demonstrated that the combined use of corn steep liquor (CSL) and vitamins in a lab-scale bioreactor resulted in product concentration and yield that reached 18.5 g L-1 and 0.62 g g-1 respectively. Although simultaneous saccharification and fermentation (SSF) could not enhance succinic acid production, a fed-batch fermentation strategy increased succinic acid concentration and yield generating 22.4 g L-1 and 0.73 g g-1 respectively, while the mass of the platform chemical formed was enhanced by 27% as compared to the batch process. BR was explored as fertilizer substitute aiming to close the loop in the management of CPW towards development of a zero-waste process demonstrating that although the material imposed stress on plant growth, the content of potassium, phosphorus and nitrogen in the mixture increased.

A Citrus Peel Waste Biorefinery for Ethanol and Methane Production.

This paper deals with the development of a citrus peel waste (CPW) biorefinery that employs low environmental impact technologies for production of ethanol and methane. Three major yeasts were compared for ethanol production in batch fermentations using CPW pretreated through acid hydrolysis and a combination of acid and enzyme hydrolysis. The most efficient conditions for production of CPW-based hydrolyzates included processing at 116 °C for 10 min. Pichia kudriavzevii KVMP10 achieved the highest ethanol production that reached 30.7 g L-1 in fermentations conducted at elevated temperatures (42 °C). A zero-waste biorefinery was introduced by using solid biorefinery residues in repeated batch anaerobic digestion fermentations achieving methane formation of 342 mL gVS-1 (volatile solids). Methane production applying untreated and dried CPW reached a similar level (339-356 mL gVS-1) to the use of the side stream, demonstrating that the developed bioprocess constitutes an advanced alternative to energy intensive methods for biofuel production.