فهرست مطالب

Advanced Research in Microbial Metabolite and Technology - Volume:4 Issue: 1, Winter-Spring 2021
  • Volume:4 Issue: 1, Winter-Spring 2021
  • تاریخ انتشار: 1401/06/21
  • تعداد عناوین: 6
  • Maryam Azizi, Davood Zare *, Abbas Akhavan Sepahy, Mehrdad Azin Pages 1-11
    β-carotene is a lipophilic pigment that belongs to the carotenoid family, produced by plants and microorganisms as a secondary metabolite, and is the most widely utilized carotenoid in the industry. Blakeslea trispora is one of the most significant industrial sources of β-carotene production among microorganisms. The present study aims to investigate the effect of K. rhizophila as a microbial stimulant and butylated hydroxytoluene (BHT) as oxidative stress on increasing β-carotene production in B. trispora. B. trispora was cultivated in the production medium with and without butylated hydroxytoluene (BHT), and after 24 hours, 10 % K. rhizophila cultures with 1011 CFU/mL were added to each medium and incubated for another 4 days. The percentage of carotenoid isomers produced in each sample was determined using high-performance liquid chromatography (HPLC). K. rhizophila and BHT, each alone, could increase carotenoid production by 2.3 and 2.4 times (respectively) compared to the control. The maximum concentration of carotenoids (793 mg/L) was found in samples containing both BHT and K. rhizophila, representing a 7.5-fold increase over the control sample. HPLC analysis of carotenoids showed two prominent peaks, including β-carotene and γ-carotene. The main carotenoid was β-carotene and was found in all samples, followed by a lesser amount of γ-carotene. Overall, microbial stimulation and oxidative stress were effective strategies for increasing β-carotene production in this microorganism.
    Keywords: β -carotene, microbial stimulant, Oxidative stress, butylated hydroxytoluene, Kocuria rhizophila, Blakeslea trispora
  • Monireh Bahrami, Maryam Besharati *, Mansour Mashreghi, Maryam Moghadam Matin, Ahmad Reza Bahrami Pages 13-23
    Some Staphylococcus species are believed to be the main cause of bacterial infections and foodborne outbreaks. Several reports have discussed the enterotoxigenic properties of some Staphylococcus species, but due to the shortage of efficient diagnostic techniques, most studies have focused only on Staphylococcus aureus. Thus, developing a culture-independent, selective, and rapid detection method for Staphylococcus species in food products is of great importance. In this study, PCR-amplified tuf gene sequences were assessed by temporal temperature gradient gel electrophoresis (TTGE) in order to detect and differentiate between different Staphylococcus species in Iranian food samples. The PCR sensitivity and specificity were evaluated against DNA samples extracted from six Staphylococcus species, including S. aureus, S. epidermidis, S. saprophyticus, S. intermedius, S. chromogenes, and S. hominis, using a commercially available kit and a cost-effective, rapid, non-commercial boiling method. Using the boiling method, the sensitivity of the tuf PCR was 9 × 101 CFU/mL for the salami samples spiked with S. aureus, ten times less sensitive than the commercial kit. After optimizing the TTGE conditions, a species-specific TTGE pattern was obtained based on the differences between the amplified sequences from various species. This TTGE pattern was applied to detect Staphylococcus species in food samples from the market. The presence of Staphylococcus species was confirmed in 6 out of 10 tested salami products. The results demonstrate that the PCR-TTGE method is an alternative method that may be specific and sensitive enough to assess the presence of possible Staphylococcus contamination in meat processed food samples. More studies using different food samples should be considered for an in-depth analysis of bacterial contamination.
    Keywords: Staphylococcus identification, PCR, TTGE, Foodborne diseases, Enterotoxins, tuf gene
  • Elham Moein Jahromi, Ali Asghar Deldar *, Maryam Shahali Pages 25-37
    Expression of recombinant human growth hormone in E. coli requires specific measures to be more efficient. In this study, two strains of E. coli, one with a genomic expression of T7 and arabinose promoters and the other with a plasmid expression (T7 promoter), were examined. In this regard, the appropriate time for sampling strains carrying the rhGH gene in genomic or plasmid form was tested. First, the best time to add the inducer to the culture medium and different concentrations of arabinose and IPTG inducers were investigated. Separate and simultaneous use of both inducers in strains with both promoters was investigated. Next, the strains were studied in five different culture media, and TB was selected as the optimal culture medium. Finally, the optimal expression of recombinant protein in TB medium was investigated using the Taguchi test for three parameters of peptone casein, yeast extract, and glucose at three different levels. Results showed the best sampling time in genomic strains was overnight; however, in plasmid strains, it was 4 hours after induction. The best time to add the inducer in genomic strains was at the beginning of the exponential phase of bacterial growth. Furthermore, lower amounts of antibiotics were associated with higher amounts of recombinant protein production in genomic strains. In the strains that had both are and T7 promoters, simultaneous induction with both inducers, i.e., arabinose and IPTG resulted in more protein expression than the single inducer.
    Keywords: Human growth hormone, Antibiotic, promoter, culture media, Glucose, peptone casein, Yeast extract
  • Seyed Esmael Razavi *, Seyed Javad Sanei, Abdolhosein Taheri Pages 39-48
    Laccases as lignocellulolytic enzymes are commonly produced by submerged fermentation, but for more constructive production, it should be preceded by nutritional factors suitable for the fungi’s growth. In the present study, the overproduction of laccase activity resulting from nutritional factor interactions was studied in Pleurotus florida, a white-rot fungi. Response surface methodology (RSM) based on the Box-Behnken factorial design (BBD) was performed to optimize the interaction of glucose and yeast extract concentrations to maximum enzyme activity with and without copper sulfate as an inducer. The results show a quadratic model with a very low p-value (<0.0001) to explain the changes in laccase production as a function of glucose, yeast extract, and copper sulfate concentrations. Based on the coefficient of determination (R2) and mean absolute error, the RSM model provided a good quality prediction for the laccase production with all independent variables. The findings explain that a 4.4-fold increase in laccase activity occurs in the presence of copper compared to cultures without copper with an optimal concentration of glucose and yeast extract as carbon and nitrogen sources, respectively. Maximum laccase activity (5.28 UmL-1) was obtained using optimized conditions (18.70 gL-1 glucose, 8.22 gL-1 yeast extract, and 0.93 mM copper sulfate). This finding could be used to induce high laccase production on a large scale for biomass changeover systems.
    Keywords: Glucose, Nutrient-sufficient conditions, Response surface methodology, white-rot fungus, Yeast extract
  • Bahareh Bahmani, Zahra Amini-Bayat *, Mohammad Mehdi Ranjbar, Mohammad Reza Masjedi, Amir-Hassan Zarnani Pages 49-65
    Cervical cancer is one of the leading causes of death worldwide, causing approximately 500,000 new cases and 250,000 cancer deaths each year. Persistent infection with high-risk human papillomaviruses (HPVs), particularly type 16, is the primary cause of cervical cancer development and maintenance among women worldwide. The E6 therapeutic vaccines can induce strong anti-tumor T cell-mediated immune responses, such as cytotoxic T lymphocytes, that play vital roles in current therapeutic vaccine development. In our study, bioinformatics approaches and in silico analyzes, such as protein sequence retrieval, identification of conserved regions, drawing of pedigrees, prediction of T-cell epitopes, calculation of population coverage of predicted epitopes, and molecular docking, were used to predict the major histocompatibility complex (MHC) Class I and Class II T cell epitopes of HPV16 E6. Taking into account the scores from different steps, six CD8+ T cells and three CD4+ epitopes were selected. The fusion of the selected epitopes created a universal potential vaccine with a population coverage of 86.41%. The population coverage was obtained by evaluating the potential of these epitopes to elicit innate and acquired immunity. These theoretically confirmed peptides could be employed in a poly-epitope construct as a candidate vaccine for further analyses. Also, these results provide new insights into therapeutic vaccine development.
    Keywords: Bioinformatics approaches, cervical cancer, Epitope design, HPV-E6, Therapeutic vaccine
  • Faezeh Almasi, Fatemeh Salimi *, Fatemeh Mohammadipanah Pages 67-81
    Numerous medical conditions, including cancers, rheumatoid arthritis, diabetes, autoimmune diseases, osteoporosis, cardiovascular disease, and more recently, COVID-19, show close linkage to inflammation as a complex pathophysiological process. In this review, we present a comprehensive outlook on microbial-derived anti-inflammatory compounds as remarkable biomedicine drugs, focusing on their efficiency, mode of action, and limitations. Various structures of microbial anti-inflammatory compounds are introduced, including Macrolactin, Lipopeptides, Pyrrol, Quinoline, Alkaloids, Carbazole derivatives, Bicyclic depsipeptides, Flavomannin, etc. The inhibitory effects on IL-5, IL-13, ICAM-1, and PTP1B expression, PGE2 release, and increasing TGF-b production are only reported for microbial-derived anti-inflammatory compounds. According to previous studies, some species of Bifidobacterium, Streptococcus, Lactobacillus, Streptococcus, Bacillus, Streptomyces, Salinispora, Micromonospora, Talaromyces, and Faecalibacterium are bacterial genera that can produce compounds with inhibitory effects on inflammation. Also, Penicillium, Pleosporales, Aspergillus, Eurotium, Ascomycota, Eurotium, Lasiodiplodia, and Graphostroma are fungal genera of fungal species with the ability to produce anti-inflammatory metabolites. Microbial-based approaches are among the main suggested natural resources that may be able to provide novel, applicable anti-inflammation drugs in the future. Furthermore, the efficiency of existing drugs could be modulated using these new microbial anti-inflammatory compounds. This will aid in the future development of novel bio-based medications to prevent and treat numerous debilitating inflammation-related diseases.
    Keywords: Anti-inflammation, Bacteria, Drug development, Fungi, Microbial metabolites