Destruction of Mycotoxins in Poultry Waste under Anaerobic Conditions within Methanogenesis Catalyzed by Artificial Microbial Consortia

Non-thermal technologies for broiler litter processing: Microbial safety, chemical composition, nutritional value, and fermentation parameters in vitro

BACKGROUND

Annually, a massive amount of broiler litter (BL) is produced in the world, which causes soil and surface water pollution due to its high nitrogen content and microbial count. While ruminants can use this non-protein nitrogen (NPN) source for microbial protein synthesis. This issue becomes more critical when protein sources are unavailable or very expensive. One of the sources of NPN is BL which is produced at a considerable amount in the world yearly.

OBJECTIVES

This aim of this research was to conduct a survey of non-thermal technologies such as electrocoagulation (EC), ultraviolet (UV) radiation, and ultrasound (US) waves on the microbial safety and nutritional value of BL samples as a protein source in ruminant diets.

MATERIALS AND METHODS

The methodology of this study was based on the use of an EC device with 24 V for 60 min, UV-C light radiation (249 nm) for 1 and 10 min, and US waves with a frequency of 28 kHz for 5, 10 and 15 min to process BL samples compared with shade-dried samples. Chemical composition and nutritional values of processed samples were determined by gas production technique and measurement of fermentation parameters in vitro.

RESULTS

Based on the results, microbial safety increased in the samples processed with the US (15 min). The EC method had the best performance in reducing the number of fungi and mould. However, none of the methods could remove total bacteria and fungi. Digestibility of BL was similar in shade-dried, EC, and US (10 min) treatments. In general, the use of EC and US15 without having adverse effects on gas production caused a decrease in the concentration of ammonia nitrogen. In contrast, it caused a decrease in neutral detergent fibre (NDF) in the investigated substrate.

CONCLUSIONS

In general, it can be concluded that the use of US5 and EC methods without having a negative effect on the parameters of gas production and fermentation in vitro, while reducing NDF, causes a significant reduction in the microbial load, pathogens, yeast, and mould. Therefore, it is suggested to use these two methods to improve feed digestibility for other protein and feed sources.

Artificial Humic Substances as Biomimetics of Natural Analogues: Production, Characteristics and Preferences Regarding Their Use

Various processes designed for the humification (HF) of animal husbandry wastes, primarily bird droppings, reduce their volumes, solve environmental problems, and make it possible to obtain products with artificially formed humic substances (HSs) as analogues of natural HSs, usually extracted from fossil sources (coal and peat). This review studies the main characteristics of various biological and physicochemical methods of the HF of animal wastes (composting, anaerobic digestion, pyrolysis, hydrothermal carbonation, acid or alkaline hydrolysis, and subcritical water extraction). A comparative analysis of the HF rates and HS yields in these processes, the characteristics of the resulting artificial HSs (humification index, polymerization index, degree of aromaticity, etc.) was carried out. The main factors (additives, process conditions, waste pretreatment, etc.) that can increase the efficiency of HF and affect the properties of HSs are highlighted. Based on the results of chemical composition analysis, the main trends and preferences with regard to the use of HF products as complex biomimetics are discussed.

Progressive Biocatalysts for the Treatment of Aqueous Systems Containing Pharmaceutical Pollutants

The review focuses on the appearance of various pharmaceutical pollutants in various water sources, which dictates the need to use various methods for effective purification and biodegradation of the compounds. The use of various biological catalysts (enzymes and cells) is discussed as one of the progressive approaches to solving problems in this area. Antibiotics, hormones, pharmaceuticals containing halogen, nonsteroidal anti-inflammatory drugs, analgesics and antiepileptic drugs are among the substrates for the biocatalysts in water purification processes that can be carried out. The use of enzymes in soluble and immobilized forms as effective biocatalysts for the biodegradation of various pharmaceutical compounds (PCPs) has been analyzed. Various living cells (bacteria, fungi, microalgae) taken as separate cultures or components of natural or artificial consortia can be involved in biocatalytic processes under aerobic or anaerobic conditions. Cells as biocatalysts introduced into water treatment systems in suspended or immobilized form are used for deep biodegradation of PCPs. The potential of combinations of biocatalysts with physical-chemical methods of wastewater treatment is evaluated in relation to the effective removing of PCPs. The review analyzes recent results and the main current trends in the development of biocatalytic approaches to biodegradation of PCPs, the pros and cons of the processes and the biocatalysts used.