Optimization, purification and characterization of α-glucosidase inhibitors from Streptomyces costaricanus EBL.HB6 isolated in Vietnam

doi:10.21203/rs.3.rs-931347/v1

Download PDF

Research Article

Optimization, purification and characterization of α-glucosidase inhibitors from Streptomyces costaricanus EBL.HB6 isolated in Vietnam

https://doi.org/10.21203/rs.3.rs-931347/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

Background

Diabetes, a disease that has been a great burden of the treatment cost for patients and society. There are many drugs have been used to cure this disease available on the pharmaceutical market. One of the most prevalent source to produce these compounds are microorganism. Among them, Streptomyces sp. are popular microorganisms used for the production of α-glucosidase inhibitors (AGIs).

Methods and Results

In this study, different cultivation conditions were optimized to enhance the production of AGIs. Purification and evaluation of AGIs from S. costaricanus EBL.HB6 were also performed. Our results demonstrated that Streptomyces costaricanus EBL.HB6 had the highest α-glucosidase inhibitory activity among 6 Streptomyces sp. strains were isolated in Vietnam. The 16S rRNA sequencing of isolating HBC6-2 indicated 99% identity to the corresponding sequence of Streptomyces costaricanus, and was registered on GenBank with the code MT 453944.1. Streptomyces costaricanus EBL.HB6 was able to produce melanin yellow pigment, and its aerial and substrate mycelia have brown and yellow-grey pigment on ISP2 cultivating medium, respectively. The α-glucosidase inhibitory activity of the supernatant was increased by a factor of 1.2 under optimal conditions (media containing 1.5% glucose, 1.2% yeast extract at 28°C, initial pH of 6.5, and culture time for 120 h) in comparison with the initial media and condition. The purified efficacy of a-glucosidase inhibitors was 5% with a retention factor of 0.71 on thin-layer chromatography and IC₅₀value of 9.59 mg/mL.

Conclusions

Streptomyces costaricanus EBL.HB6 strain was selected, purified and evaluated for its highly producible of α-glucosidase inhibitors.

Molecular Biology

Molecular Genetics

Purification

optimal conditions

Streptomyces costaricanus EBL.HB6

α-glucosidase inhibitors (AGIs)

The Actinomycetes sp. belongs to the group of endophytic microorganisms that can produce a myriad of inhibitors against pathogenic microorganisms [1]. Therefore, several studies have investigated its role as a bio-control factor including promoting plant growth, reducing the risk of the infectious pathogen, and enhancing the viability of plants under different conditions [2]. Actinomycetes took a major part in the population of root microorganisms so they easily transmit to the plant and become an endophytic body. The population includes both Streptomyces and non-Streptomyces appear in plant tissues [3]. A large number of publications in microbial compounds have reported that 45% of substances originated from Actinomycetes, 38% were from mushrooms, and 17% were from bacteria. Actinomycetes are one of the most important microorganisms due to the majority of their secondary metabolites including enzymes, antibiotics, antifungals go to industrial, agricultural, and pharmaceutical markets [4].

Most of these biologically active substances were discovered from terrestrial Actinomycetes which are recognized as a reliable resource for the production of antibiotics and new pharmaceutical compounds. The Actinoplane sp. and Streptomyces sp. are the most popular species that capable of producing α-glucosidase inhibitors (AGIs) such as acarbose of Actinoplanes [5, 6], AGIs from Streptomyces sp. [7, 8], and other aminoglycosides, anthracyclin, glycopeptide…[9].

The ratio of discovering pharmaceutical compounds from endophytic Actinomycetes is higher than soil-borne and plan Actinomycetes. A new antibiotic, Naphthomycin-K, was first discovered from endophytic Streptomyces sp. from Maytenus Hookeri-a medicinal plant that has effects against cancer. Two compounds, 5,7-dimethoxy-4-phenylcoumari and 5,7-dimethoxy-4-p-methoxylphenylcoumarin, strongly inhibited cancer growth which is frequently isolated from different plant species. Recently, they are also found in endophytic S. aureofaciens [10]. Methyllelaiophylin of S. melanosporofaciens inhibited α-glucosidase with IC₅₀ at 10 µM [11]. Kaur (2016) isolated several antibiotics from endogenous Streptomyces, Micromonospora, Microbiospora, Nocardia on the leaves of the neem tree (Azadirachta indica A. Juss.) [12]. A new active substance was extracted from Streptomyces sp. OUCMDZ-3434 isolating from algae samples. These are 2 new AGIs that have been discovered. Wailupemycins H (1) with Ki/IC₅₀ were 16.8/19.7 µM, and Wailupemycins I (2) with Ki/IC₅₀ were 6.0/8.3 M [9]. Wei (2017) isolated 24 compounds from the fermentation broth of S. xanthophaeus that were numbered from 1–24, and their chemical formula was elucidated by NMR. The authors have identified 3 compounds including daidzein, genistein, and gliricidin which inhibited α-glucosidase in vitro with IC₅₀ were 174.2; 36.1 and 47.4 µM, respectively. The results showed the inhibitory activity was higher than that of acarbose [13].

In this study, HBC6-2 was choosed for its high production of AGIs from 6 different strains that were isolated from orange trees originated from Hoa Binh, Viet Nam. We next optimized culture conditions to increase the production and purified AGIs for further study.

Microorganism

The Streptomyces sp. strain was provided by Soil Microbiology of Laboratory, Institute of Biotechnology, Vietnam Academy of Science and Technology including HBC3-2, HBC5-1, HBC6-2, HBR5-1, HBR9-6, and HBR10-2. This Streptomyces sp. strains were isolated from the samples of root, stem, and leaf of Cao Phong orange, Hoa Binh, Vietnam.

The strain Streptomyces sp. was cultivated in ISP2 medium (g/L): 4 yeast extract, 10 malt extract, 4 dextrose, and pH 7.2. The condition for culturing Streptomyces sp. was 28°C, shaking at 200 rpm and 120 h.

Chemical reagent

Acarbose, dimethyl sulfoxide (DMSO), and p-nitrophenyl-α-D-glucopyranoside (pNPG) were obtained from Sigma-Aldrich. K₂HPO₄, KH₂PO₄, Na₂HPO₄, NaH₂PO₄ were obtained from Merck. Alpha-glucosidase, glucose, dextrose, glycerol, yeast extract, and malt extract were purchased from Biobasic INC (Canada). Sephadex^TM G-75 was purchased from GE Healthcare Bio-Sciences AB (Sweden). All other chemicals are analytical grade, otherwise stated.

Fermentation

The Streptomyces sp. strain was streaked on the agar plate. After 7 days, colonies appeared with yellow-brown color. A single one was inoculated in a 100 mL propagation medium. After 72 h, it was fermented in a medium consisting of (g/L): 12 yeast extract, 15 glucose, pH 6.5 in 120 h at 28°C and 200 rpm to collect the fermentation broth.

Enzyme Assay

The tests were performed in a 96-well microplate setup with slight modifications [14]. A reaction mixture of 100 µL of 1-2 U/mL α-glucosidase was dissolved in 0.1 M sodium phosphate buffer and mixed with 10 µL fermentation broth (or CHCl₃/Act extract) and 40 µL of phosphate buffer solution, and then was subjected to pre-incubation in 5 min at 30°C. Continuously, 100 μL of 4-nitrophenyl-α-D-glucopyranoside 0.1 M in phosphate buffer was added as substrate after pre-incubation. Next, the samples were incubated at 30°C for 10 min to allow α-glucosidase to react with 4-NPG and produce 4-nitrophenol. After the incubation, the formation of 4-nitrophenol in each well was measured at 405 nm. The inhibitory activity was calculated using

DNA isolation, identification of chosen strain

The 16S rDNA sequencing method was used to identify the isolated strain. Genomic DNA isolation was used to extract DNA from a potent AGIs strain [15]. The isolated DNA was amplified by PCR. The conserved gene of 16S rRNA was amplified by using 9F (5′-AGAGTTTGATCCTGGCTC-3′) as the forward primer and 926R (5′-CCGTCAATTCCTTTGAGTT-3′) as the reverse primer. The amplified gene was sequenced on ABI PRISM 3100 Avant Genetic Analyzer. Sequence alignments were analyzed using the program MegAlign DNAStar

Culture conditions optimization

Time and temperature culture

Unless otherwise stated, S. costaricanus EBL.HB6 was cultivated in a 250 mL flask with 50 mL ISP2 medium at 28°C with 200 rpm shaking and pH of 7.2. Extracellular extract from the culturing medium was obtained and α-glucosidase inhibitory activity tests were carried out after 24, 48, 72, 86, 120, 144, 168, and 192 h to select the best culture time.

To select optimum temperature for the AGIs production, S. costaricanus EBL.HB6 was cultured at diﬀerent temperature from 28 to 37°C on ISP2 medium at pH 7.2.

Carbon source and concentration

The eﬀect of various additional carbon sources on the a-glucosidase inhibitors production including: starch soluble, sucrose, maltose, glucose, dextrose, and lactose at the concentration of 0.4% (w/v) was investigated. S. costaricanus EBL.HB6 was grown in 250 mL shaking ﬂasks containing 50 mL of the medium with 1% of malt extract, 0.4% yeast extract (w/v), and 0.4% (w/v) of diﬀerent carbon sources.

The levels of carbon source giving the highest AGIs production varied from 0.4 to 3.5% (w/v).

Nitrogen source and concentration

The eﬀect of various additional nitrogen sources including peptone A, peptone B, (NH₄)₂SO₄, yeast extract, and malt extract at the concentration of 1.0% (w/v) was employed. In addition, the ISP2 medium was used to as a control sample.

The levels of nitrogen giving the highest AGIs production varied from 1.0 to 1.8% (w/v).

Initial medium pH
Fermentation in different pH culture media (pH 6, 6.5, 7, 7.5, and 8) was used to determine the ideal initial pH in flask culture, which was changed with either 1 N NaOH or 1 N HCl. All the tests were conducted in triplicate.

Purification of the α-glucosidase inhibitors

The S. costaricanus EBL.HB6 was cultured in the optimized fermentation media at pH 6.5, incubated at 28°C for 120 h. 100 mL of the cell culture broth was centrifuged at 12500 rpm in 15 min. The fermentation broth was extracted with ethanol (80%) for 30 min, then centrifuged at 12500 rpm in 15 min. The collected liquid was lyophilized. Αlpha-glucosidase inhibitory activity of the re-solubilized solution was determined, and then applied to a Sephadex^TM G-75 column (0.6 × 26 cm) pre-equilibrated with 0.02 M phosphate buffer (pH 6.8) at a flow rate of 25 mL/hr until the OD 280 nm was < 0.01. The column was then eluted with 0.02 M phosphate buffer (pH 6.8). The eluted fractions of 2 mL were collected (20 fractions). The active fraction was lyophilized and alkalized to pH 10-11 by 0.1 N NaOH after re-solubilized by phosphate buffer. 10 mL of solution was extracted with n-butanol (1:1; v/v) three times. The upper phase was obtained by centrifugal at 4000 rpm in 15 min to collect n-butanol extract residue.

The n-butanol extract residue was re-solubilized in 30 ml of CHCl₃/Act solvent (1:1; v/v), at 40°C, overnight, and then centrifuged at 4000 rpm for 15 min to remove residue. The extract was evaporated dissolved in DMSO.

The purified AGIs were tested and detected by thin-layer chromatography (TLC) as well as infrared spectroscopy to determine the presence of the substance group. 5 μL of samples were chromatographed on TLC plates (Merck, Germany) with solvent (n-butanol: acetone: H₂O; 5:1:4; v/v/v), then they were sprayed with iodine.

Evaluation of the IC₅₀ value

The IC₅₀ value was obtained by examination of the inhibition activity of α-glucosidase of purified AGIs at different levels: 5-60 mg/mL. The line graph equation was established as a function of the purified AGIs concentration (x) and inhibitory activity (y) [16]. The IC₅₀ value is the level of purified AGIs value that inhibit 50% α-glucosidase activity.

Statistical analysis

All measurements were carried out in triplicate. The means were presented for the averages of experiments.

Screening of α-glucosidase inhibitory activity for Streptomyces sp. strains

The fermentation broth of 6 strains of Streptomyces sp. was examined with α-glucosidase activity. Streptomyces sp. HBC6-2 displayed the highest α-glucosidase inhibitory activity by 68.98% among Streptomyces sp. strains (Fig. 1a). The strain Streptomyces sp. HBC6-2 produced melanin yellow pigments, non-fragmenting substrate mycelia (hypha diameter around 10 mm), and formed spiral spores containing 10-50 spores. The color of the aerial and substrate mycelia of Streptomyces sp. HBC6-2 was gray-brown and yellow-brown (Fig. 1b).

16S rRNA sequencing of Streptomyces sp. HBC6-2 was identified. BLAST results of 16S rRNA from HBC6-2 strain indicated that this 16S rRNA segment showed 99.69% identity with 16S rRNA from S. costaricanus MR7 (KY753206), 99.59% to S. costaricanus MJM5482 (FJ799179) (Fig. 1c). It was registered on GenBank with the code MT 453944.1.

Culture conditions optimization

To determine the optimal conditions for producing AGIs from S. costaricanus EBL.HB6, the culture parameters such as culture time, temperature, carbon, and nitrogen of source at different levels and initial pH were investigated.

Effect of culture time and temperature

The incubation time for AGIs production by S. costaricanus EBL.HB6 was carried out in the ISP2 medium at 28°C with shaking 200 rpm, and an initial pH of 7.2. After 120 h of culture, the a-glucosidase inhibitory activity of extracellular extracts of S. costaricanus EBL.HB6 reached maximal values of 70.15%. Then, it slightly decreased and after 192 h of culture as low as 42.63% (Fig. 2a).

The temperature did not significantly affect the AGIs activity of the S. costaricanus EBL.HB6. This strain had stable activity in the temperature range 28-37°C, however, it is capable of producing highly active α-glucosidase inhibitors at 28°C (Fig. 2b).

Effect of carbon source at diﬀerent levels

Glucose-containing medium showed the highest α-glucosidase inhibitory activity of 72.42%, followed by other medium supplemented with sucrose (44.68%); malt extract (32.05%). However, starch soluble and maltose-containing medium showed the lowest inhibition activity (Fig. 2c).

Dextrose was replaced by glucose dramatically increased the AGIs production by S. costaricanus EBL.HB6 from 68.3% in the media containing 0.4% (w/ v) of glucose to the maximum 76.25% at glucose (1.5 %), and then gradually decreased to 57.5% in the medium containing 3.5% of glucose (Fig. 2d).

Effect of nitrogen source at its concentration

Culture medium supplementing different with nitrogen source exhibited different α-glucosidase inhibitory activity (Fig. 3a). Yeast extract adding media enhance the inhibition activity of the crude extract by 77.07%. In contrast, Peptone B and malt extract supplementing media exhibited a lower inhibition activity of 51.44% and 52.72%, respectively, and the lowest one is (NH₄)₂SO₄ containing media.

Especially, the fermented media only containing of yeast extract (1.2%) increased α-glucosidase inhibitory to 87.1% while ISP2 media was reached 68.98% (Fig. 3b).

Effect of initial pH

Five different initial pH 6, 6.5, 7, 7.5, and 8 were examined for their effect on AGIs production by S. costaricanus EBL.HB6. The optimal initial culture pH for AGIs production by S. costaricanus EBL.HB6 was 6.5 (Fig 3c). At this pH, the α-glucosidase inhibitory activity of extracellular extracts of S. costaricanus EBL.HB6 reached maximal inhibitory activity of 83.58%. An initial culture pH lower or higher than 6.5 reduced AGIs production by S. costaricanus EBL.HB6. These findings suggested that the pH medium has a considerable impact on AGIs production by S. costaricanus EBL.HB6.

Determination of α-glucosidase inhibitory activity under optimal conditions

The S. costaricanus EBL.HB6 strain was grown in the optimal medium containing 1.5% of glucose, 1.2% of yeast extract, at 28°C with initial pH of 6.5 for 120 h. The result showed the α-glucosidase inhibitory activity of extracellular extracts of S. costaricanus EBL.HB6 was 84.97% (Fig. 3d). These results were 1.2 times higher than those obtained before optimization (69.77%).

Purification of a-glucosidase inhibitors

The ethanol extract of S. costaricanus EBL.HB6 was purified by passage over a Sephadex^TM G-75 column. These fractions were tested for α-glucosidase inhibitory activity and all were positive (Fig. 4a). Fraction 9-13 showed the highest α-glucosidase inhibitory activity of 84% (fraction 10) and 50% to 70.53%, respectively. Fractions 10 were then extracted by n-butanol three times and n-butanol extract residue was re-solubilized in CHCl₃/Act solvent to obtain purified inhibitors.

The purity of the purified inhibitors was assessed by TLC methods. A spot with Rf=0.71 was observed (Fig. 4b- land 4) and the yield of the purification process was 5% and exhibited inhibition of α-glucosidase activity was 45.47% (Table 1).

We next investigated the α-glucosidase inhibitor activity of purified AGIs by measuring the IC₅₀ value. The purified AGIs were dissolved in DMSO at different levels. The IC₅₀of purified AGIs was 9.59 mg/mL (Fig. 4c).

The FT-IR spectrum showed that major functional groups appeared such as Ar-H vibration in aromatic ring, imide region, C=C oscillation in the aromatic ring, and oscillation outside mp Ar-H (Fig. 4d).

Several studies reported that actinobacteria were more prevalent in the discovery of α-glucosidase inhibitors. Abdulkhair (2018) isolated 55 strains of marine Actinomycetes, of which, only 7 strains were found to have α-glucosidase inhibitory activity [17]. S Ganesan, S Raja, P Sampathkumar, K Sivakumar and T Thangaradjou [18] identified 41 bacteria strains that exhibited glucosidase inhibitory activity from 181 isolated strains of marine actinobacteria [18]. The study by Cansigno and his colleagues discovered that Veracruz seaweed was capable of synthesizing α-amylase and AGIs [19].

The culture duration of S. costaricanus EBL.HB6 produced the AGIs shorter than Streptomyces sp. strain OUCMDZ-3434 (8 days) [9], possibly because of S. costaricanus EBL.HB6 produced the secondary metabolite during the growth and development of Actinomycetes. In which, Streptomyces sp. OUCMDZ-3434 produced a phenolic compound that takes a long time to produce. During nutrient depletion, metabolites are generally generated during the late growth stage of bacteria [20]. This finding was in agreement with the earlier study in which in the presence of glucose, the synthesis of acarbose, AGIs used to treat diabetes type 2, was produced [6, 21].

The AGIs was purified from the culture supernatant showed α-glucosidase inhibitory activity of 45.47% and a spot with a coefficient of Rf = 0.71 on TLC (Fig. 4b, lane 4). The purified inhibitor showed the final yield of the purification procedure was 5% (Table 1).

These results of the FT-IR spectrum suggested that AGIs production S. costaricanus EBL.HB6 could be an alkaloid but not a protein from Streptomyces sp. AD7 [17], or phenolic compounds from Streptomyces sp. OUCMDZ-3434 [9], S. xanthophaeus [13], or dibutyl phthalate from the strain S. melanosporofaciens [22]. This result is further evidence of the diversity in AGIs production by different Streptomyces sp. strains. Purified AGIs from different Streptomyces sp. strains may be obtained the different AGIs.

In our recent study, we determined the IC₅₀ of the n-butanol extract was 13.89 µg/mL from Oceanimonas smirnovii EBL6, while acarbose (Sigma) was 31.16 µg/mL [23]. In this study, IC₅₀ value of purified AGIs was 9.59 µg/mL. This may be suggested that S. costaricanus EBL.HB6 had potential for the treatment of type II diabetes for further study. Previously, ethyl acetate extracted containing AGIs from Streptomyces sp. IPBCC. b. 15. 1539 with IC₅₀ value was 0.047 µg/mL [16]; 21.17 µg/mL from Streptomyces sp. S2A [7]; 3.1 mg/mL A. oryzae N159-1 [24]; 5.625 µg/mL from A. awamori [25]; 1.25 µg/mL from Streptomyces strain PW638 [8]; 0.062 mg/mL from Streptomyces sp. TVS1 [26]; 500 µg/mL from Arthrobacter enclensis [27]. Daidzein, genistein, and gliricidin from S. xanthophaeus with IC₅₀ values of 174.2, 36.1 and 47.4 µM, respectively [13]; two new AGIs from Streptomyces sp. OUCMDZ-3434 with IC₅₀ values of 19.7 and 8.3 µM, respectively [9]. So, IC₅₀ value may be related to the purity level of the extracts or compound.

In conclusion, the isolating HBC6-2 was chosen for its high production of AGIs from 6 different Streptomyces sp. strains isolated from the samples of root, stem, and leaf of Cao Phong orange and its was registered on GenBank with the code MT 453944.1.

The optimal culture medium for fermentation of AGIs from S. costaricanus EBL.HB6 composed of (g/L): glucose 15, yeast extract 12; pH 6.5. The optimal incubated conditions for the production were 120 h, 28°C, and shaking speed of 200 rpm. Combination of all the optimal conditions, the α-glucosidase inhibition activity exhibited the highest point at 84.97%, increased by a factor of 1.2 times in comparison with the initial condition. In addition, we successfully purified and evaluated of IC₅₀ value of AGIs from S. costaricanus EBL.HB6. The significant inhibitory α-glucosidase activity of S. costaricanus suggests its potential utility as an alternative to make biosimilars products for the treatment of type II diabetes.

Acknowledgement

This work was financially supported by the Vietnam Academy of Science and Technology: “Isolation, selection, and purification of secondary metabolites inhibiting α-glucosidase, oriented for the treatment of type 2 diabetes from microorganism isolated in Vietnam”. Code number KHCBSS.01/19-21. Vietnam Academy of Science and Technology. 2019-2021.

Funding

This study was funded by the Vietnam Academy of Science and Technology with the grant number of KHCBSS.01/19-21 (2019-2021).

Conflict of interest

The authors declare no competing interests.

Availability of data and material

The sequence of bacteria strain was deposited in GenBank with accession no. MT 453944.1. All data generated or analysed during this study are included in this published article.

Ethics declarations

Ethical statement

This article does not contain any studies with human participants or animals performed by any of the authors.

Consent for publication

All authors have approved the submitted version and give consent for publication.

Author’s Contribution

DTT and NTT designed the experimental setup, assisted with data analysis and manuscript preparation. MVH performed experiments of screening of S. costaricanus EBL.HB6. NPDN and DTMA performed optimization of α-glucosidase inhibitory activity. NTT and PTHT purified and determined on the IC₅₀ value of the AGIs. DTT initiated the project, read and approved the final manuscript. All authors read and approved the final manuscript.

Lee SO, Choi GJ, Choi YH, Choi YH, Jang KS, Park DJ, Kim CJ, Kim JC (2008) Isolation and characterization of endophytic actinomycetes from Chinese cabbage roots as antagonists to Plasmodiophora brassicae. J Microbiol Biotechnol 18(11):1741–1746
Strobel G, Daisy B, Castillo U, Harper J (2004) Natural products from endophytic microorganisms. J Nat Prod 67(2):257–268
Shutsrirung A, Chromkaew Y, Pathom-Aree W, Choonluchanon S, Boonkerd N (2013) Diversity of endophytic actinomycetes in mandarin grown in northern Thailand, their phytohormone production potential and plant growth promoting activity. J Soil Sci Plant Nutr 59:322–330
Sharma M, Dangi P, Choudhary M (2014) Actinomycetes: Source, identification, and their applications. Int J Curr Microbiol App Sci 3(2):801–832
Wang YJ, Liu LL, Feng ZH, Liu ZQ, Zheng YG (2011) Optimization of media composition and culture conditions for acarbose production by Actinoplanes utahensis ZJB-08196. Microb Biotechnol 27:2759–2766
Sun LH, Li MG, Wang YS, Zheng YG (2012) Significantly enhanced production of acarbose in fed-batch fermentation with the addition of S-adenosylmethionine. Microb. Biotechnol 22:826–831
Siddharth S, Vittal RR (2018) Evaluation of antimicrobial, enzyme inhibitory, antioxidant and cytotoxic activities of partially purified volatile metabolites of marine Streptomyces sp.S2A. Microorganisms 6:72
Meng P, Zhou XX (2012) α-Glucosidase inhibitory effect of a bioactivity guided fraction GIB-638 from Streptomyces fradiae PWH638. Med Chem Res 21(12)
Chen Z, Hao J, Wang L, Wang Y, Kong F, Zhub W (2016) New α-glucosidase inhibitors from marine algae-derived Streptomyces sp. OUCMDZ-3434. Sci Rep. doi:10.1038/srep20004
Qin S, Xing K, Jiang JH, Xu LH, Li WJ (2010) Biodiversity, bioactive natural products and biotechnological potential of plant-associated endophytic actinobacteria. Appl Microbiol Biotechnol 89(3):457–473
Lee D, Woo JK, Kim D, Kim M, Cho SK, Kim JH, Park SP, Lee HY, Riu KZ, Lee DS (2011) Antiviral activity of methylelaiophylin, an alpha-glucosidase inhibitor. J Microbiol Biotechnol 21(3):263–266
Kaur N (2016) Endophytic actinomycetes from Azadirachta indica A. Juss.: Characterization and anti-microbial activity. Int J Adv Res 4(6):676–684
Wei J, Zhang XY, Deng S, Cao L, Xue QH, Gao JM (2017) α-Glucosidase inhibitors and phytotoxins from Streptomyces xanthophaeus. Nat Prod Res 31(17):2062–2066
Koh WY, Uthumporn U, Rosma A, Irfan AR, Park YH (2018) Optimization of a fermented pumpkin-based beverage to improve Lactobacillus mali survival and α-glucosidase inhibitory activity: A response surface methodology approach. Food Sci Hum Wellness 7:57–70
Quyen DT, Dao TT, Nguyen SLT (2007) A novel esterase from Ralstonia sp. M1: gene cloning, sequencing, high-level expression and characterization. Protein Expr Purif 51(2):133–140
Lestari Y, Rahminiwati M, Velina Y (2015) Metabolites activity of endophytic Streptomyces sp. IPBCC. b.15.1539 from Tinospora crispa l. miers: α-glucosidase inhibitor and anti-hyperglycemic in mice. Int J Pharm Pharm Sci 7(6):235–239
Abdulkhair WM, Abdel-All WS, Bahy RH (2018) Genetic improvement of antidiabetic alpha-glucosidase inhibitor producing Streptomyces sp. Int J Pharm Pharm Sci 10(5):77–84
Ganesan S, Raja S, Sampathkumar P, Sivakumar K, Thangaradjou T (2011) Isolation and screening of α -glucosidase enzyme inhibitor producing marine actinobacteria. Afr J Microbiol Res 5(21):3437–3245
Landa-Cansigno C, Hernández-Domínguez EE, Monribot-Villanueva JL, Licea-Navarro AF, Mateo-Cid LE, Segura-Cabrera A, Guerrero-Analco JA (2020) Screening of Mexican tropical seaweeds as sources of α-amylase and α-glucosidase inhibitors. Algal Res. doi:https://doi.org/10.1016/j.algal.2020.101954
Bibb MJ (2005) Regulation of secondary metabolism in Streptomycetes. Curr Opin Microbiol 8(2):208–215
Wei SJ, Cheng X, Huang L, Li KT (2010) Medium optimization for acarbose production by Actinoplanes sp. A56 using the response surface methodology. Afr. J Biotechnol 9:1849–1854
Lee DS (2000) Dibutyl phthalate, an α-glucosidase inhibitor from Streptomyces melanosporofaciens. J Biosci Bioeng 89(3):271–273
Nguyen THT, Tang DYY, Chew KW, Nguyen TL, Le TH, Nguyen TC, Hoang TY, Nguyen TT, Nguyen TT, Show PL, Do TT (2021) Discovery of α glucosidase inhibitors from marine microorganisms: Optimization of culture conditions and medium composition. Mol Biotechnol. doi:https://doi.org/10.1007/s12033-021-00362-3
Kang MG, Yi SH, Lee JS (2013) Production and characterization of a new α-glucosidase inhibitory peptide from Aspergillus oryzae N159-1. Mycobiology 41(3):149–154
Singh B, Kaur A (2015) Antidiabetic potential of a peptide isolated from an endophytic Aspergillus awamori. J Appl Microbiol 120:301–311
Nguyen NT, Nguyen CTG, Luong AH, Nguyen MC (2019) Studying on appropriate conditions for the production of α-amylase and α-glucosidase inhibitors from Streptomyces sp. TVS1. CTUJS 55(2):49–56
Mawlankar RB, Dharne MS, Dastager SG (2020) Isolation of potent alpha–glucosidase inhibitor from a novel marine bacterium Arthrobacter enclensis. SN Applied Sciences 2:474

Table 1. Purification efficacy of a-glucosidase inhibitiors

Purification steps	Amounts (g)	Yield (%)	a-glucosidase inhibition (%)
The fermentation broth	1.814		84.97
Sephadex^TM G-75 (fraction 10)	0.4261	23.49	84.0
n-butanol extract	0.1492	8.2	54.37
The purified AGIs	0.0907	5.0	45.47

Graphicalabstract.pdf

Download PDF

Version 1

posted

You are reading this latest preprint version

Optimization, purification and characterization of α-glucosidase inhibitors from Streptomyces costaricanus EBL.HB6 isolated in Vietnam

Status:

Version 1

Abstract

Figures

Introduction

Materials And Methods

Enzyme Assay

Results

Discussion

Declarations

Funding

References

Tables

Supplementary Files

Status:

Version 1