Antimicrobial Activity and Characterization of Pomegranate Peel-Based Carbon Dots

This investigation reports the use of agrowaste pomegranate peels as an economical source for the production of fluorescent carbon dots (C-dots) and their potential application as an antimicrobial agent. The carbon dots were prepared through low-temperature carbonization at 200°C for 120 min. The obtained C-dots were found to be small in size and exhibited blue luminescence at 350 nm. Further, the synthesized C-dots were characterized with the help of analytical instruments such as DLS, UV-visible, FT-IR, TEM, and fluorescence spectrophotometer. Antimicrobial activity of the C-dot PP was estimated by the agar diffusion method and MIC. S. aureus and K. pneumoniae are showing susceptibility towards C-dot PP when compared to the standard and showing a moderate activity against P. aeruginosa and resistance towards E. coli. The obtained C dot PPs were found to be around 5-9 nm in size confirmed from DLS analysis and supported by TEM. The synthesized C-dots were investigated to understand their microbial efficiency against pathogens and found to have antimicrobial efficiency. These results suggest that pomegranate peels are a potential source of carbon dots with antimicrobial efficiency.

Effect of Antibiotics on the Microbial Efficiency of Anaerobic Digestion of Wastewater: A Review

Recycling waste into new materials and energy is becoming a major challenge in the context of the future circular economy, calling for advanced methods of waste treatment. For instance, microbially-mediated anaerobic digestion is widely used for conversion of sewage sludge into biomethane, fertilizers and other products, yet the efficiency of microbial digestion is limited by the occurrence of antibiotics in sludges, originating from drug consumption for human and animal health. Here we present antibiotic levels in Chinese wastewater, then we review the effects of antibiotics on hydrolysis, acidogenesis and methanogenesis, with focus on macrolides, tetracyclines, β-lactams and antibiotic mixtures. We detail effects of antibiotics on fermentative bacteria and methanogenic archaea. Most results display adverse effects of antibiotics on anaerobic digestion, yet some antibiotics promote hydrolysis, acidogenesis and methanogenesis.

Carcass traits, commercial cuts, tissue composition, intake, digestibility, and performance of Sindhi bulls subjected to feed restriction

ABSTRACT: This study showed the effect of feed restriction on performance, nitrogen balance (NB), microbial protein synthesis, carcass traits and meat cut of the thirty-two Sindhi non-castrated males (296 ± 21.3 kg initial BW and 21 ± 1.5 months old). All bulls were distributed in a completely randomized design with four treatments (feed restriction levels) (0, 15, 30, and 45% in total dry matter -DM) and the data were subjected to analysis of variance and regression. Nutrient intake, NB, final BW, total gain, feeding efficiency, carcass gain, hot and cold carcass weight, subcutaneous fat thickness, commercial cuts and fat tissue decreased linearly (P<0.05) by feed restriction level. A linear increased on digestibility of DM, NDFap, total carbohydrates and on the proportion of muscle tissue, as well as quadratic increase on non-fibrous carbohydrates and bone tissue percentage with the restriction level imposed on bulls (P<0.05). The feed restriction did not affect (P>0.05) the digestibility of crude protein, synthesis and microbial efficiency, deposition efficiency, longissimus dorsi area and muscle + fat/bone ratio. The feed restriction reduced intake and consequently performance, carcass traits and meat cuts of Sindhi bulls; however, it promoted a reduction in the N excretion, which can be important if conducted a subsequent compensatory weight gain.

Effects of enriched mesquite piperidine alkaloid extract in diets with reduced crude protein concentration on the rumen microbial efficiency and performance in lambs

The objective of this study was to evaluate the effects of enriched mesquite piperidine alkaloid (MPA) extract at 31 mg/kg of dry matter (DM) in diets with 16% or 13% of crude protein (CP) compared to a diet with 16% CP without additive (control) and diets with monensin (MON) at 31 mg/kg DM and 16% or 13% CP. The intake, ingestive behaviour, apparent digestibility, body weight gain, microbial protein synthesis and nitrogen balance were evaluated. A total of 30 uncastrated crossbred Santa Inês × Bergamasca lambs were used and allocated in a completely randomized design. No effects of additives on dry matter (DM), organic matter (OM), neutral detergent fibre (NDF), and non-fibre carbohydrate (NFC) intake were observed in diets with 16% and 13% CP compared to the control diet. The total digestible nutrient intake (g/kg BW) for the diet with MPA 13% CP was lower than for the control diet, while the metabolisable energy intake (MJ/kg BW) did not differ between diets. The DM feeding rate (g/min) was reduced for the diet with MON 13% CP compared to the control diet. There was no difference between MON or MPA with CP 16% or 13% and the control diet in the digestibility of DM, OM, NFC, and NDF. MON in the diet with 13% CP reduced the BW gain, which differed from the control diet, while MPA 13% CP did not differ from the control diet. The microbial protein synthesis efficiency was higher for diets with MPA compared to MON 13% CP and the control diet. Dietary nitrogen retention (g/kg metabolic weight) was lower in diets with 13% CP that differed from the diets with 16% CP. The nitrogen retained as a percentage of ingested and digested nitrogen was unchanged with the use of MPA or MON 13% CP due to lower urinary nitrogen excretion. The MPA 13% CP diet does not affect the performance of lambs by increasing the microbial synthesis efficiency in the rumen.

The in vitro Efficacy of Two Microbial Strains and Physicochemical Effects on their Aflatoxin Decontamination in Poultry Feeds

Background: Contamination of animal feeds with aflatoxigenic fungi is a challenge to livestock farmers worldwide. Aflatoxins are very toxic fungal metabolites that are associated with carcinogenic, mutagenic, teratogenic, and estrogenic effects. The toxins affect animal productivity and may lead to deaths, causing enormous economic losses. Aflatoxin decontamination is a challenge to the feed industry, despite the several approaches available. This study investigated the efficacy of two microbial isolates, Bacillus spp (B285) and Yeast strain (Y833), in reducing Aflatoxin concentration in poultry feeds in comparison with a commonly used commercial chemical binder, Bentonite. The influence of the poultry feed matrix, pH, and temperature on the aflatoxin reducing activity by the two microorganisms was also explored. Results: The in vitro studies showed that the two microorganisms and the chemical binder reduced aflatoxins by over 74% of the original concentration. The chemical binder registered the highest reduction at 93.4%; followed by Y833 (83.6%), then the combination of Y833 and B285 (77.9%); and lastly B285 (74.9%). There was no significant (p>0.05) influence of temperature on the toxin reducing capacity of all the agents tested. The pHs 4.5 and 6.5 did not have a significant effect on the performance of both chemical binder and biological agents, however, the former performed better at pH 6.5 with 95% aflatoxin reduction compared to the microorganisms. The aflatoxin reducing activity was lower in presence of feeds compared to that in Phosphate Buffered Saline except for Y833 where no difference was observed. Conclusions: Although the feed components affected the aflatoxin reducing capacity of the test materials, the chemical binder was more effective than the microbial agents. Yeast strain was more effective than the bacterial strain in reducing the aflatoxin levels, however, both are promising strategies for countering the aflatoxin challenges in animal feeds. In response to the advocacy for use of biological control agents, there is need for more investigations to establish the safety of the microorganisms, the mechanism of decontamination and safety of the products; the optimum concentrations that can reduce aflatoxins in feeds to permissible levels and the effect of the toxin contamination levels on microbial efficiency.