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To develop high quality probiotics for shrimp larviculture, the effects of a photosynthetic purple sulphur bacterium WF identified as Ectothiorhodospira shaposhnikovii on survival and development of Litopenaeus vannamei larvae were evaluated in vivo. The larvae exhibited a better survival rate after administration of strain WF compared to the probiotic Rhodopseudomonas palustris. To investigate the effect of dose and dosing frequency, strain WF was added to larvae, stages nauplius 6 to zoea 3, at three different doses and dosing frequencies. Larval treatment with strain WF twice at 106 cfu/ml exhibited significantly higher survival compared to the other doses and dosing frequencies as well as the control. The effect on water quality was assessed by applying strain WF to larvae, stages nauplius 6 to postlarvae 1, under conditions of zero water exchange and one-third water exchange. The larvae exhibited higher survival and faster growth when treated under conditions of zero water exchange. No significant difference was detected in the levels of three water quality parameters and in vibrio counts between these two conditions. Therefore, E. shaposhnikovii WF acts both as a bioremediation agent and nutrient source and can benefit shrimp larvae if given at an appropriate dose and dosing frequency. Strain WF, a moderate halophile, shows great promise as a water additive in improving water quality and providing nutrition for shrimp larviculture.

In: Beneficial Microbes
Authors: , , , , , and

Abstract

The Aspergillus terreus strain HNGD-TM15 that was isolated from soil grown with rosemary was shown to efficiently degrade aflatoxin B1 (AFB1). Specifically, AFB1 was degraded by the strain’s fermentation broth at a maximum degradation rate of 98.3%. HPLC and LC-MS analyses detected a degradation product with an m/z ion value of 312.0636. Its molecular formula was C18H39NO3, which was tentatively identified as 2-amino-1, 3,4-octadecatriol. Based on LC-MS results and further analysis, it was revealed that a series of reactions, such as decomposition, reduction (lactone ring hydrogenation) and substitution (hydrolysis), occurred during the degradation of AFB1. Therefore, A. terreus HNGD-TM15 has a great potential for application in the detoxification of AFB1 contaminating food and feed products.

In: World Mycotoxin Journal

Edible insects have been proposed as an understudied food whose cultivation could be increased with global population growth. However, the bioactivators and bioactivities of bee pupae are poorly studied. In this paper, the active ingredients of bee pupa powder were analysed, and novel bee pupa polypeptides (BPP) were obtained through protein hydrolysis with alkaline protease. Two purified polypeptide components (BPP-21 and BPP-22) were isolated and purified on a diethylaminoethyl-sepharose fast flow column and a Sephadex G-25 column, and identified using size exclusion chromatography-high performance liquid chromatography and amino acid composition analyses. Due to its higher cell proliferation activity, BPP-22 was selected for further study of its immunomodulatory activity and mechanismin vivo andin vitro. The analysis of immunomodulatory activity showed that BPP-22 significantly increased the body weight growth rate, organ index, macrophage phagocytosis, delayed-type hypersensitivity reaction, cytokine level (interleukin (IL)-2 and interferon (IFN)-γ), immunoglobulin (Ig) levels (IgA, IgG, and IgM), and routine blood indexes in cyclophosphamide-treated immunosuppressed mice (P<0.01). Mechanistic research in RAW264.7 cells showed that BPP-22 might promote the secretion of cytokines (IL-2, tumour necrosis factor-α and IFN-γ) and the production of nitric oxide by increasing homologous mRNA expression and could exert immunomodulatory activity by increasing the phosphorylation of ERK and p38, and modulating the expression of intranuclear transcription factors (EIK-1, MEF-2 and CREB) in the MAPK signalling pathway. These findings are helpful for promoting the application of bee pupae as potential immunomodulatory agents and protein supplements.

In: Journal of Insects as Food and Feed

Crop Circle ACS 430 is a newly developed active crop canopy reflectance sensor with three fixed wavebands covering red (670 nm), red-edge (730 nm) and near infrared (NIR,780 nm) regions. The objective of this study was to determine how much improvement the Crop Circle ACS430 would achieve for estimating rice yield potential at key growth stages as compared with a GreenSeeker sensor. Four N rate experiments were conducted in 2012 and 2013 at Jiansanjiang Experiment Station of China Agricultural University, located in Sanjiang Plain, Heilongjiang Province, Northeast China. The results indicated that in-season estimate of yield (INSEY) calculated with GreenSeeker normalized difference vegetation index (NDVI) and ratio vegetation index (RVI) could only explain 18% and 13% of variability in yield potential without additional topdressing N application (YP0) at panicle initiation stage and there was no significant relationship at heading stage. By comparison, the INSEY calculated with the best Crop Circle vegetation indices explained 35% and 58% of YP0 variability at these two stages, respectively. At stem elongation stage, the Crop Circle ACS-430 sensor (best R2=0.68) did not have any significant improvement over GreenSeeker RVI (R2=0.65). More studies are needed to further evaluate Crop Circle ACS-430 sensor for precision N management of rice under on-farm conditions.

In: Precision agriculture '15

Evaluation of combined toxicity and exploring the corresponding mechanism is of great significance in characterising the interactions of mixed mycotoxins. This study used high content analysis and multiple evaluation models to estimate combined toxic hepatotoxicity in HepG2 cells, due to aflatoxin B1, zearalenone and deoxynivalenol, which are often detected simultaneously in the same grain sample. All mycotoxins induced cell loss in HepG2 cells in a concentration dependent manner. The combined toxic effects observed by multiple evaluation models (CA, IA and CI) suggested a similar mechanism and dominant synergistic effects for binary and ternary combinations. Based on reactive oxygen species, intracellular glutathione (GSH), and mitochondrial transmembrane potential (MMP) assessment, the synergistic mechanisms may be associated with mitochondrial damage by reducing GSH and MMP.

In: World Mycotoxin Journal

Abstract

To figure out the copper metabolism features in vivo and evaluate the potential risk of copper residue in tissues of black soldier fly larvae (BSFL) and their by-products, the effects of oral copper exposure of 0, 50, 500 and 1000 mg/kg (Control, Cu50, Cu500 and Cu1000) on growth performance and dynamic copper accumulation in the fat body, cuticle of BSFL and the rearing residue were investigated in a 12-days rearing trial. The results showed that, the body weight and length, and body protein content of BSFL were improved by exposure to 50 mg/kg copper, but reduced by exposure to 500 and 1000 mg/kg copper, as well as that of the pre-pupa rate. Under the copper exposure of 500 and 1000 mg/kg, the copper concentrations in the larval fat body were high at the early developmental stage, but sharply reduced to be 8.1 ± 0.3 mg/kg within 12 days with no significant differences among groups. Similarly, the copper concentrations in the cuticle also decreased rapidly to be 46.3 ± 2.9 and 91.3 ± 9.4 mg/kg in the Cu500 and Cu1000 groups within 12 days, but they were significantly higher than those of the control (8.1 ± 0.3 mg/kg) and Cu50 (10.1 ± 1.1 mg/kg) groups. The linear regression analysis between copper exposure doses and copper concentrations in the rearing residues indicated that the latter are dose- and time-dependent. Overall, the growth performance and body protein content of BSFL were improved by low copper exposure, but reduced by high copper exposure. The oral copper could be excluded from larval fat body and cuticle rapidly, and be largely accumulated in the rearing residues. Therefore, little risk of copper residue in the main tissues of post larvae or pre-pupae of black soldier fly (BSF), but higher risk of it in the rearing residues could be anticipated. Our results provide valuable information for safety assessment of copper residues in BSF products and by-products.

In: Journal of Insects as Food and Feed

Ochratoxins are a mycotoxin family frequently found in agricultural commodities worldwide and pose a potential health risk to humans and animals. To obtain large amounts of high-purity ochratoxins for food safety monitoring and toxicological research, a novel and effective method was established for simultaneous purification of ochratoxin A (OTA) and ochratoxin B (OTB) from a wheat culture inoculated with an ochratoxin-producingAspergillus strain. The inoculated wheat culture was first extracted with methanol:water (80:20, v/v), followed by one or two cleanup procedures involving acid-assisted liquid-liquid extraction and gel permeation chromatography. Subsequently, target analytes were separated and collected using preparative high performance liquid chromatography. Finally, a combined approach of ultra-high performance liquid chromatography, ultraviolet spectrophotometry and mass spectrometry was applied for purity analysis and structural identification of the obtained toxins. As a result, 100 g of an inoculated wheat culture yielded 69 mg of OTA and 6 mg of OTB with purities greater than 98%. This proposed method might serve as a valuable reference to obtain expensive ochratoxin standards. To the best of our knowledge, this is the first report on simultaneous preparation of OTA and OTB from artificially inoculated wheat culture.

In: World Mycotoxin Journal

Abstract

Irritable bowel syndrome (IBS), a disorder of gut-brain interaction, is associated with abdominal pain and stool frequency/character alterations that are linked to changes in microbiome composition. We tested whether taxa differentially abundant between females with IBS vs healthy control females (HC) are associated with daily gastrointestinal and psychological symptom severity. Participants (age 18-50 year) completed a 3-day food record and collected a stool sample during the follicular phase. They also completed a 28-day diary rating symptom intensity; analysis focused on the three days after the stool sample collection. 16S rRNA gene sequencing was used for bacterial identification. Taxon abundance was compared between IBS and HC using zero-inflated quantile analysis (ZINQ). We found that females with IBS (n = 67) had greater Bacteroides abundance (q = 0.003) and lower odds of Bifidobacterium presence (q = 0.036) compared to HC (n = 46) after adjusting for age, race, body mass index, fibre intake, and hormonal contraception use. Intestimonas, Oscillibacter, and Phascolarctobacterium were more often present and Christensenellaceae R-7 group, Collinsella, Coprococcus 2, Moryella, Prevotella 9, Ruminococcaceae UCG-002, Ruminococcaceae UCG-005, and Ruminococcaceae UCG-014 were less commonly present in IBS compared to HC. Despite multiple taxon differences in IBS vs HC, we found no significant associations between taxon presence or abundance and average daily symptom severity within the IBS group. This may indicate the need to account for interactions between microbiome, dietary intake, metabolites, and host factors.

In: Beneficial Microbes