Nutrient-efficient catfish-based aquaponics for producing lamb's lettuce at two light intensities.

BACKGROUND: Aquaponic systems are sustainable processes of managing water and nutrients for food production. An innovate nutrient-efficient catfish-based (Clarias gariepinus) aquaponics system was implemented for producing two cultivars of two leafy vegetables largely consumed worldwide: lamb's lettuce (Valerianella locusta var. Favor and Valerianella locusta var. de Hollande) and arugula (Eruca vesicaria var. sativa and Eruca sativa). Different growing treatments (4 × 2 factorial design) were applied to plants of each cultivar, grown at two light intensities (120 and 400 µmol m-2 s-1). During growth, several morphological characteristics (root length, plant height, leaf number, foliage diameter and biggest leaf length) were measured. At harvest, plants were weighed and examined qualitatively in terms of greenness and health status. Additionally, leaf extracts were obtained and used to determine total phenolic contents, antioxidant capacities, and levels of cytotoxicity to Caco-2 intestinal model cells. RESULTS: After a 5-week growth period, both lamb's lettuce cultivars presented high levels of greenness and health status, at both light intensities, particularly the var. de Hollande that also showed higher average performance in terms of plant morphology. In turn, arugula cultivars showed lower levels of greenness and health status, especially the cultivar E. vesicaria var. sativa submitted to direct sunlight during growth. In addition, plant specimens submitted to higher levels of light intensity showed higher contents in antioxidants/polyphenols. Cultivars with a higher content in antioxidants/polyphenols led to higher Caco-2 cell viability. CONCLUSION: For successful industrial implementation of the aquaponics technology, different and optimized acclimatizing conditions must be applied to different plant species and cultivars. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

ASBR applied to the treatment of biodiesel production effluent: effect of organic load and fill time on performance and methane production.

The effect of organic matter and fill time on anaerobic sequencing batch reactor (5 L, 30 °C, 8-h cycles, 50 rpm) efficiency has been analyzed. Organic matter was increased by the influent concentration. Fill times investigated were in the batch mode and fed-batch followed by batch. In the batch mode organic matter removal were 93%, 81%, and 66% for influent concentration of 500, 1,000, and 2,000 mgCOD/L (0.6, 1.29, and 2.44 g COD/L.d), respectively. At 3,000 mgCOD/L (3.82 gCOD/L x d) operational stability could not be achieved. Removal efficiency was improved by increasing the fill time, and was 85% for the 1,000 mgCOD/L condition and fill times of 2 and 4 h, and 80 and 77% for the 2,000 mgCOD/L condition and fill times of 2 and 4 h, respectively. Hence, gradual feeding seemed to improve and to smooth the profiles of organic matter and volatile acids along the cycle with 78 to 96 NmLCH4/gCOD.

Procedimentos de biossegurança realizados por cirurgiöes-dentistas e laboratórios durante a confecçäo de próteses dentárias / Bio-security procedures accomplished by surgeon-dentists and laboratories during dental making prosthesis

Infecçäo cruzada entre consultório odontológico e laboratório de prótese pode ocorrer quando procedimentos de biossegurança näo säo executados adequadamente. O objetivo do presente trabalho foi verificar como cirurgiöes-dentistas e laboratórios estäo realizando procedimentos para prevençäo de infecçäo cruzada durante a confecçäo de próteses. Foram entrevistados 100 cirurgiöes-dentistas e 60 protéticos do Vale do Paraíba, Estado de Säo Paulo, por meio de questionários sobre a realizaçäo de procedimentos de biossegurança. Entre os laboratórios visitados, 20 foram escolhidos de forma aleatória, para se quantificar a presença de microrganismos na pedra-pomes em uso, e em 10 se quantificou a presença de microrganismos em superfícies críticas (tornos e escovas de polimento, bancadas e peças de mäo). Nos 20 laboratórios estudados, existia contaminaçäo em todas as amostras de pedra-pomes (média de 4,46 logufc/g,) e a quantidade de microrganismos encontrados nas superfícies, em ágar-sangue, foi em média 41,87 ufc por placa. A partir destes dados, observa-se a necessidade de alertar os cirurgiöes-dentistas para a obrigatoriedade da desinfecçäo dos moldes, modelos e das peças protéticas, antes do envio aos laboratórios e após o seu retorno