Background: Citric acid is produced in insignificant quantities in Iran. Despite its great range of utilizations, and from another aspect, high level of production of sugarcane bagasse, the related problems arising from maintenance of this acid require thinking of a measure in the direction of its optimal usage and production. Objectives: The objective of the present study is to obtain effectual variables in producing citric acid from sugarcane bagasse through Solid State Fermentation (SSF) method using Aspergillus niger mold and to optimize its mass production by employing Taguchi method. Materials and Methods:The effective parameters such as spore inoculation level, methanol percentage, solvent type, spore age, humidity percentage, initial pH of substrate, fermentation period and temperature, initial sugar percentage, autoclaving duration, nitrogen source and etc. were studied for producing citric acid from sugarcane bagasse with respect to Tagouchi method. Results: By considering the findings obtained from the tests, the highest production rate of citric acid g/kg out of untreated sugarcane bagasse is 75.45 based on the consumed sugar and a yield of 15.1 g/kg of sugarcane was achieved per day. Application of sodium hydroxide and acid pretreated sugarcane bagasse increased the production of citric acid in such a fashion that the production rates were 97.81 g/kg and 87.32 g/kg of sugarcane bagasse, respectively, compared to sodium hydroxide and acid untreated sugarcane bagasse. Conclusions:The obtained findings in the present study indicated that sugarcane bagasse is an ideal substrate in producing citric acid and the aforementioned process could be considered as a beneficial and cost-effective method in citric acid production.

Saccharomyces boulardii, a subspecies of Saccharomyces cerevisiae, is a well-known eukaryotic probiotic with many benefits for human health. In the present study, a recombinant strain of S. boulardii was prepared to use as a potential oral vaccine delivery vehicle. In this sense, a ura3 auxotroph strain of S. boulardii CNCM I-745 (known as S. cerevisiae HANSEN CBS 5926, Yomogi®) was generated using CRISPR/Cas9 methodology. Then a gene construct encoding a highly immunogenic protein, ovalbumin (OVA), was prepared and transformed into the ura3- S. boulardii. To facilitate the transport of the recombinant immunogen across the intestinal barrier, a claudin-targeting sequence from Clostridium perfringens enterotoxin (CPE) was added to the C-terminus of the expression cassette. The recombinant S. boulardii strain expressing the OVA-CPE fusion protein was then administered orally to a group of mice, and serum IgG and fecal IgA levels were evaluated by ELISA. Our results demonstrated that anti-OVA IgG in serum significantly increased in test group (P < 0.001) compared to control groups (receiving wild type S. boulardii or PBS), and the fecal IgA titer was significantly higher in test group (P < 0.05) than control groups. In parallel, a recombinant S. boulardii strain expressing the similar construct lacking C-terminal CPE was also administered orally. The result showed an increased level of serum IgG in group receiving yeasts expressing the CPE negative construct compared to control groups; however, the fecal IgA levels did not increase significantly. In conclusion, our findings indicated that the yeast S. boulardii, as a delivery vehicle with possible immunomodulatory effects, and c-CPE, as a targeting tag, synergistically assist to stimulate systemic and local immunity. This proposed recombinant S. boulardii system might be useful in the expression of other antigenic peptides, making it as a promising tool for oral delivery of vaccines or therapeutic proteins.

PurposeFimH (the adhesion fragment of type 1 fimbriae) is implicated in uropathogenic Escherichia coli (UPEC) attachment to epithelial cells through interaction with mannose. Recently, some studies have found that UPEC can thrive intracellularly causing recurrent urinary tract infection (UTI). Almost all vaccines have been designed to induce antibodies against UPEC. Yet, the humoral immune response is not potent enough to overcome neither the primary UTI nor recurrent infections. However, DNA vaccines offer the possibility of inducing cell mediated immune responses and may be a promising preventive tool.Materials and MethodsIn this study, we employed two different open reading frames within mammalian (mam) and wild type (wt) codons of fimH gene. Optimized fragments were cloned in pVAX-1. Expression of the protein in COS-7 was confirmed by western blot analysis after assessing pVAX/fimH(mam) and pVAX/fimH(wt). The constructs were injected to BALB/c mice at plantar surface of feet followed by electroporation.ResultsThe mice immunized with both constructs following booster injection with recombinant FimH showed increased interferon-γ and interleukin-12 responses significantly higher than non-immunized ones (p<0.05). The immunized mice were challenged with UPEC and then the number of bacteria recovered from the immunized mice was compared with the non-immunized ones. Decreased colony count in immunized mice along with cytokine responses confirmed the promising immune response by the DNA vaccines developed in this study.ConclusionIn conclusion, DNA vaccines of UPEC proteins may confer some levels of protection which can be improved by multiple constructs or boosters.

Our study suggested that the levels of mycotoxins in products should be detected before buying and be discarded from human consumptive cycle if the grains are contaminated more than allowable limit. Background: A variety of agricultural products are exposed to fungal contamination from the early stages of planting, until their final consumption. T-2 mycotoxin is toxic to humans and to all animal species, it is mainly produced by the various Fusarium species including; F. sporotrichioides, F. poae, F equiseti, and F. acuminatum, and occasionally by other genera species, therefore, measuring T-2 toxin levels is very important in cereals. Objectives: We examined the occurrence and levels of T-2 mycotoxin in grains for human consumption. Materials and Methods: Rice, barley and wheat samples, 23, 16 and 7 respectively, were collected from the staple stores of nine food cooking centers in Tehran. After pulverizing the samples, they were extracted using a methanol-water solution (70:30), then analysed with an enzyme linked immunosorbent assay (ELISA), based on the monoclonal antibodies, the amount of T-2 mycotoxin was measured in their extracts. Results: All of the tested samples were contaminated with T-2 toxin at different levels ranging from 7.9 to 65.9 µg/kg (mean: 17.9 ± 2.1). Wheat samples had the highest level of contamination at approximately 42.4 µg/kg (± 8.4). However, both barley and rice were also affected with contamination levels of 18.3 (±2) and 12.5 (± 0.56) µg/kg respectively. Conclusions: Although the majority of samples were based on Iranian national standards, a small number of specimens (13.9 %) were contaminated at higher than acceptable limits. The extent of the impurities with T-2 toxin is an indicator of the current normal prevalence of mycotoxins in agricultural products destined for human consumption in this country, and the risk of exposure to the chronic effects of this toxin. Overall, this study showed that the level of mycotoxins in food products should be checked before they are bought or consumed.

Uropathogenic Escherichia coli (UPEC) bacteria are the principal cause of urinary tract infections (UTI). Because these bacteria propagate intracellularly, the cellular immune response is an important factor in UTIs. Therefore, we designed a genetic construct to induce a cellular immune response. In order to develop a genetic construct that induces strong cellular immunity against this pathogen, we used the fimH synthetic gene according to mammalian codon usage, and the gene expression was compared with wild type codon usage. Initially, we designed two constructs, pVAX/fimH mam and pVAX/fimH wt, which contain mammalian and wild type codon usage, respectively. The Cos-7 cell line was transfected separately with a complex of pVAX/fimH mam-ExGene 500 poly cationic polymer and pVAX/fimH wt-ExGene 500 poly cationic polymer. Expression of the fimH gene in both constructs in COS7 cells was confirmed by RT-PCR, SDS-PAGE, and Western blotting. Both of the pVAX/fimH cassettes expressed inserted fimH genes (mam and wt) in Cos-7 cells. Our results suggest that codon optimization successfully expressed the fimH gene because the fimH gene with mammalian codon usage is compatible with the eukaryotic expression system. Therefore, mammalian codon usage could be appropriate in a pVAX/fimH construct as a DNA vaccine.