Torrefaction interpretation through morphological and chemical transformations of agro-waste to porous carbon-based biofuel.

In the current study, two agro-waste lignocellulosic corncob (CC) and rice husk (RH) were thermally torrefied at 200-300 °C into a porous carbon-enriched biofuel. The scanning electron microscopy (SEM) of produced biofuel confirmed the rounded, homogenous, and spherical structure of the produced biofuels with higher porosity at a temperature between 250 and 300 °C with 60 min retention time. Brunauer-Emmett-Teller (BET) analysis indicated the high surface area (CC: 1.19-2.87 m2 g-1 and RH: 1.22-2.67 m2 g-1) and pore volume (CC: 1.23-2.81 ×10-3 m3 g-1 and RH: 1.46-2.58 ×10-3 m3 g-1). Crystallinity index decline percent (CC= 62.87% and RH=57.10%) estimated thermal stability and rise in amorphous cellulose reformation during (250-300 °C)/60 min that would efficiently hydrolyze during oxidative pyrolysis carbon reactive sites the rise in surface area and total pore's volume, having higher conversion rate as compared to raw materials. Carbon content was upgraded to 94% by eliminating hydrogen and oxygen from lignocellulosic agro-waste to produce energy-dense CC and RH. The lignin macromolecule transformation extent was estimated by O/C trend, which was equal to 63% and 47% for CC and RH, respectively, at 300 °C for 60 min. Due to low bulk density and pre-grinding energy requirements, torrefied biofuel with decomposed fibrous structure have lower transportation costs.

Cyclic peptide: a safe and effective alternative to synthetic aflatoxin B1-competitive antigens.

Aflatoxin B1 (AFB1) is one of the major mycotoxins, which naturally occurs in food and agricultural products. In this study, a cyclic peptide (CVPSKPGLC) mimicking AFB1 was used to develop a biotinylated peptide-based immunoassay (bp-ELISA) for AFB1 determination. This cyclic peptide was isolated from a commercially available phage-displayed random 7-mer cyclic peptide library, and then synthesized chemically. Instead of phage particles, the peptide was biotinylated and used to detect AFB1 by bp-ELISA, with an IC50 of 0.92 ng/mL, which was approximately 60-fold better than that of phage ELISA. Good recoveries (83-102%) were obtained in spiked rice and corn samples, which were further validated by high-performance liquid chromatography-fluorescence detector. As better sensitivities (0.92-1.21 ng/mL) were obtained by bp-ELISA even using selected anti-AFB1 antibodies prepared previously in laboratory, this cyclic peptide is suitable as a substitute for synthetic competitive AFB1 antigens in food contamination monitoring. Graphical abstract.

VHH Antibodies: Reagents for Mycotoxin Detection in Food Products.

Mycotoxins are the toxic secondary metabolites produced by fungi and they are a worldwide public health concern. A VHH antibody (or nanobody) is the smallest antigen binding entity and is produced by heavy chain only antibodies. Compared with conventional antibodies, VHH antibodies overcome many pitfalls typically encountered in clinical therapeutics and immunodiagnostics. Likewise, VHH antibodies are particularly useful for monitoring mycotoxins in food and feedstuffs, as they are easily genetic engineered and have superior stability. In this review, we summarize the efforts to produce anti-mycotoxins VHH antibodies and associated assays, presenting VHH as a potential tool in mycotoxin analysis.

Significance of additives to enhance the acceptance of poison bait in poultry rodents of Haripur, Khyber Pakhtunkhwa, Pakistan.

Rodent infestation on poultry farms incurs heavy economic losses to this industry by causing feed loss and disease introduction. Development and continuous improvement of rodents control techniques are vital to minimize and control the damages caused by rodents. Here, we test the feed preference of rodents for locally available and palatable food grains viz. millet (whole), wheat (cracked) and rice (broken) and taste additives namely whole egg (5%), eggshell (5%), peanut cracked (5%) and yeast (2%) that were offered mixed in millet-wheat (50:50 by wt.) bait. We tested the preferences of different food additives through a process of feed choice mechanism. We applied two different techniques to compare the preference of mixed feed baits, these techniques included no-choice with multiple choice feeding tests and paired choice with multiple choices feeding tests. The results indicated that consumption of bait with added whole egg was significantly higher (p > 0.05). Further test for its effectiveness as a carrier for rodenticides revealed 56%, 82% and 92%, reduction in rodent activities with zinc phosphide (2%), coumatetralyl (0.0375%) and Brodifacoum (0.005%) respectively. Our results point to a need on continuous improvement of feed baits by using different combinations to effectively control the rodent infestation.

Camelization of a murine single-domain antibody against aflatoxin B1 and its antigen-binding analysis.

Aflatoxin B1 (AFB1), a highly toxic mycotoxin, always contaminated in a variety of agricultural products. Camelid variable domain of heavy chain antibody (VHH) is a noteworthy reagent in immunoassay, owing to its excellent characteristics. Immunization of camelid animals is a straightforward strategy to produce VHHs. In this study, to avoid the dependence on the large animals, the camelized, murine antibody (cVHs) against AFB1 was prepared in vitro based on the identities between murine VH and camelid VHH and then to develop an immunoassay for AFB1. A murine anti-AFB1 VH fragment (VH-2E6) was selected for camelization through replacement of conserved hydrophobic residues in framework region 2 (FR2) (cVH-FR2), point mutation at position 103 in the FR4 region (cVH-103), and CDR3-grafted with a high AFB1-affinity VHH (cVH-Nb26). The cVH-Nb26 had a yield of 5 mg/L as refolded protein expressed from Escherichia coli and 10 mg/L expressed from Pichia pastoris. Compared with anti-AFB1 single-chain fragment variable (scFv) 2E6, cVH-Nb26 performed more than 20-fold enhancement of AFB1-binding interactions. Although the AFB1-affinity of cVH-Nb26 cannot meet the application requirement in the present form, our study provides effective strategies for preparation of camelized antibody in vitro, which could be a promising immunoreagent for AFB1 detection.

Recovery of reproductive function of female zebrafish from the toxic effects of microcystin-LR exposure.

Fish has a strong resistance to microcystins (MCs), cyclic heptapeptide cyanotoxins, known as endocrine disrupting chemicals (EDCs) which are released during cyanobacterial blooms and many laboratory and field studies have found the hepatic recovery of fish from the MCs exposure. The aim of the present study was to investigate the recovery mechanisms of reproductive function of adult zebrafish (Danio rerio) from microcystin-LR (MC-LR) exposure. Therefore, adult female zebrafish were exposed to 0, 1 or 50 µg/L of MC-LR for 21days and transferred to MC free water for another 21 days to investigate the recovery. After MC-LR exposure, marked histological lesions in the gonads, decreased the percentage of mature oocytes, decreased number of spawned eggs, decreased fertilization and hatching rates were observed. MC-LR exposure increased the concentration of 17ß-estradiol (E2), testosterone (T) and vitellogenin (VTG) in female zebrafish. Some gene transcriptions of the hypothalamic-pituitary-gonad (HPG) axis significantly changed. The protein levels of 17ßhsd and cyp19a remarkably increased in the MC-LR exposure groups. However, our laboratory observation also indicates that zebrafish transferred from microcystin exposure to toxin-free water and reared for 21 days exhibited a nearly complete recovery of reproductive functions, including histological structure, increased the percentage of matured oocytes and spawned eggs, stable hormone levels, well-balanced transcriptional and translational levels. These results indicate that after MC-LR exposure, the reproductive impairments in zebrafish are also reversible likewise hepatic recovery seen by different studies in fish. Future studies should be conducted to explore a better understanding of the recovery mechanisms of fish from microcystins exposure.