Lysohexaenetides A and B, linear lipopeptides from Lysobacter sp. DSM 3655 identified by heterologous expression in Streptomyces / 中国天然药物

Lysobacter harbors a plethora of cryptic biosynthetic gene clusters (BGCs), albeit only a limited number have been analyzed to date. In this study, we described the activation of a cryptic polyketide synthase (PKS)/nonribosomal peptide synthetase (NRPS) gene cluster (lsh) in Lysobacter sp. DSM 3655 through promoter engineering and heterologous expression in Streptomyces sp. S001. As a result of this methodology, we were able to isolate two novel linear lipopeptides, lysohexaenetides A (1) and B (2), from the recombinant strain S001-lsh. Furthermore, we proposed the biosynthetic pathway for lysohexaenetides and identified LshA as another example of entirely iterative bacterial PKSs. This study highlights the potential of heterologous expression systems in uncovering cryptic biosynthetic pathways in Lysobacter genomes, particularly in the absence of genetic manipulation tools.

Advances in several important antimicrobial lipopeptids from Bacillus spp / 生物工程学报

Bacillus spp. are probiotics and can secrete a variety of natural antimicrobiol active substances, of which lipopeptides are an important class. Up to now, about 90 lipopeptides have been identified, and most of them are cyclic lipopeptides. surfactin, iturin, fengycin, bacillomycin and polymyxins are widely studied, and the first three have huge potential for application due to their properties of surfactants and anti-fungal, anti-bacterial, anti-viral, anti-tumor and anti-inflammatory functions. In this paper, the research progress in the structure, function, synthesis regulation, separation, purification and production of surfactin, iturin and fengycin was reviewed. Synthetic biology is a vital means to increase the yield of lipopeptides, and in the future, lipopeptides can be used in crop cultivation, animal farming, food, medicine and petroleum industries as well as environmental protection. Future research should be strengthened on the discovery of new lipopeptides, synthesis of high-activity lipopeptides, economical production of lipopeptides on a large scale and their safety evaluation.

Pam2CSK4 (TLR2 agonist) induces periodontal destruction in mice

Abstract Lipoproteins are important bacterial immunostimulating molecules capable of inducing receptor activator of nuclear factor-κB (RANKL) and osteoclast formation in vitro and in vivo . Although these molecules are present in periodontopathogenic bacteria, their role in periodontitis is not known. In this study, we used Pam2CSK4 (PAM2), a synthetic molecule that mimics bacterial lipoprotein, to investigate the effects of lipoproteins on periodontitis in mice. C57BL/6 male mice were randomly divided into three experimental groups: 1) Negative control group: animals received vehicle injection; 2) Positive control group: animals received injection of Escherichia coli lipopolysaccharide (LPS); 3) PAM2 group: animals received PAM2 injection. All the injections were performed bilaterally every other day into the palatal mucosa between first and second molars. After twenty-four days, the animals were euthanized to assess alveolar bone volume (micro-CT), cellular and extracellular composition in the gingiva (stereometric analysis), and osteoclast numbers (TRAP staining). Treatment with either PAM2 or LPS induced gingival inflammation, as demonstrated by increased infiltration of inflammatory cells and enhanced angiogenesis, associated with a smaller number of fibroblasts and decreased extracellular matrix. Importantly, treatment not only with LPS but also with PAM2 resulted in a larger number of TRAP+ multinucleated osteoclasts and significant loss of alveolar bone. Collectively, our data demonstrate that PAM2 can induce gingival inflammation and bone loss in mice, broadening the avenues of investigation into the role of lipoproteins in the pathogenesis of periodontal disease.

Pam2CSK4 (TLR2 agonist) induces periodontal destruction in mice

Abstract Lipoproteins are important bacterial immunostimulating molecules capable of inducing receptor activator of nuclear factor-κB (RANKL) and osteoclast formation in vitro and in vivo . Although these molecules are present in periodontopathogenic bacteria, their role in periodontitis is not known. In this study, we used Pam2CSK4 (PAM2), a synthetic molecule that mimics bacterial lipoprotein, to investigate the effects of lipoproteins on periodontitis in mice. C57BL/6 male mice were randomly divided into three experimental groups: 1) Negative control group: animals received vehicle injection; 2) Positive control group: animals received injection of Escherichia coli lipopolysaccharide (LPS); 3) PAM2 group: animals received PAM2 injection. All the injections were performed bilaterally every other day into the palatal mucosa between first and second molars. After twenty-four days, the animals were euthanized to assess alveolar bone volume (micro-CT), cellular and extracellular composition in the gingiva (stereometric analysis), and osteoclast numbers (TRAP staining). Treatment with either PAM2 or LPS induced gingival inflammation, as demonstrated by increased infiltration of inflammatory cells and enhanced angiogenesis, associated with a smaller number of fibroblasts and decreased extracellular matrix. Importantly, treatment not only with LPS but also with PAM2 resulted in a larger number of TRAP+ multinucleated osteoclasts and significant loss of alveolar bone. Collectively, our data demonstrate that PAM2 can induce gingival inflammation and bone loss in mice, broadening the avenues of investigation into the role of lipoproteins in the pathogenesis of periodontal disease.

Construction and optimization of engineered Bacillus subtilis for surfactin production / 生物工程学报

Surfactin has great potential applications in enhancing oil recovery, agriculture, pharmaceuticals, foods and beverages, and cosmetics due to its extraordinary surface activity, biodegradability, anti-bacterial activity and biocompatibility. Enhancing surfactin production by engineering surfactin-producer and optimizing culture conditions is the key of its industrial production and subsequent applications. In this study, the effect of fatty acid synthesis pathway on surfactin synthesis was investigated, and Bacillus subtilis THBS-2 and THBS-8 with high surfactin titer were constructed by overexpressing key genes involved in the fatty acid synthesis pathway. To optimize culture condition, the amount and adding time of isopropyl-beta-D-thiogalactopyranoside (IPTG) and amino acids were studied, and a two-stage culture method was obtained: IPTG (final concentration: 1.25 mmol/L) and leucine (final concentration: 5 g/L) were added at 3 h, leucine (final concentration 5 g/L) and condensed culture medium (5 mL) were added at 24 h. Applying this strategy, the surfactin titer of B. subtilis THBS-2 reached to 24 g/L in shake flask at 48 h and up to 34 g/L after 68 h fermentation in a 30-L fermentor. The results provide basis for large-scale production and broad application of surfactin.

Differential proteomics research of Bacillus amyloliquefaciens and its genome-shuffled saltant for improving fengycin production

Abstract In the previous study, we used genome shuffling to improve fengycin production of the original strain Bacillus amyloliquefaciens ES-2-4. After two rounds of genome shuffling, a high-yield recombinant FMB72 strain that exhibited 8.30-fold increase in fengycin production was obtained. In this study, comparative proteomic analysis of the parental ES-2-4 and genome-shuffled FMB72 strains was conducted to examine the differentially expressed proteins. In the shuffled strain FMB72, 50 differently expressed spots (p < 0.05) were selected to be excised and analyzed using Matrix-Assisted Laser Desorption/Ionization Time of Flight/Time of Flight Mass Spectrometry, and finally 44 protein spots were confidently identified according to NCBI database. According to clusters of orthologous groups (COG) functional category analysis and related references, the differentially expressed proteins could be classified into several functional categories, including proteins involved in metabolism, energy generation and conversion, DNA replication, transcription, translation, ribosomal structure and biogenesis, cell motility and secretion, signal transduction mechanisms, general function prediction. Of the 44 identified proteins, signaling proteins ComA and Spo0A may positively regulate fengycin synthesis at transcriptional level. Taken together, the present study will be informative for exploring the exact roles of ComA and Spo0A in fengycin synthesis and explaining the molecular mechanism of fengycin synthesis.

Activador tisular del plasminógeno recombinante para el tratamiento de la vegetación intracardíaca en un lactante de muy bajo peso al nacer / Recombinant tissue plasminogen activator treatment for intracardiac vegetation in a very low birth weight infant

Las nuevas opciones de tratamiento prolongan la hospitalización y aumentan las infecciones intrahospitalarias bacterianas y fúngicas, pero también mejoran la sobrevida de los recién nacidos hospitalizados en la unidad de cuidados intensivos neonatales. Las infecciones fúngicas invasivas en neonatos están asociadas con una morbimortalidad significativa. También pueden diseminarse a órganos específicos y causar endocarditis, endoftalmitis, artritis séptica, nefropatía obstructiva y meningitis. En el caso de la endocarditis, se recomiendan tratamientos antimicóticos sistémicos agresivos y, en algunos casos, la intervención quirúrgica del neonato. Informamos el caso de un lactante prematuro, de bajo peso al nacer, con vegetación intracardíaca. Esta es una complicación rara y potencialmente mortal de infecciones fúngicas invasivas. El paciente recibió tratamiento con caspofungina y un activador tisular del plasminógeno recombinante, en vez de una intervención quirúrgica.

Developing treatment options have resulted in prolonged admission and increased bacterial and fungal nosocomial infections as well as improved survival in neonatal intensive care unit. Invasive fungal infections in newborns are associated with significant morbidity and mortality and can cause endorgan dissemination such as endocarditis, endophthalmitis, septic arthritis, obstructive nephropathy and meningitis. Endocarditis requires aggressive systemic antifungal therapy and sometimes surgical intervention in neonates. We report a low birth weight premature infant with intracardiac vegetation that is rare and a life-threatening complication of invasive fungal infections. He was treated with caspofungin and recombinant tissue plasminogen activator in stead of surgical intervention.

Successful treatment of fungal endophthalmitis using intravitreal caspofungin / O primeiro relato de caspofungina intravítrea no tratamento de endoftalmite fúngica

ABSTRACT Fungal endophthalmitis is a rare condition often associated with poor prognosis. We present a case of postoperative acute fungal endophthalmitis caused by the yeast-like fungus Stephanoascus ciferrii (Candida ciferrii). The fungus was resistant to fluconazole, voriconazole, and amphotericin B but susceptible to caspofungin. Because the degree of vitreal penetration of caspofungin after its intravenous administration is unclear, we performed multiple intravitreal injections, first with 50 µg/0.1 ml and then with 250 µg/0.1 ml caspofungin. Despite the recurrence of symptoms, intravitreal injection of caspofungin finally abolished the inflammation and achieved ambulatory vision that persisted until 1 year of follow-up. To our knowledge, this is the first report of S. ciferrii endophthalmitis and its successful treatment with intravitreal caspofungin.

RESUMO Endoftalmite fúngica é uma ocorrência rara, muitas vezes associada com mau prog nóstico. Apresentamos um caso de endoftalmite fúngica aguda pós-operatória causada por fungo de levedura incomum, Stephanoascus ciferrii (Candida ciferrii). O fungo foi resistente ao fluconazol, ao voriconazol e à anfotericina B e susceptível à caspofun gina. Dado que a penetração vítrea da caspofungina após administração intravenosa não é clara, optou-se por realizar múltiplas injecções intravítreas, primeiro de 50 µg e depois de 250 µg de caspofungina, e finalmente obteve-se a resolução da inflamação e a visão recuperada foi mantida por pelo menos um ano após o ocorrido. No nosso conhecimento, este é o primeiro relato de endoftalmite por Stephanoascus ciferrii e o primeiro relato de endoftalmite fúngica tratada com sucesso com caspofungina intravítrea.

Antifungical Activity of Autochthonous Bacillus subtilis Isolated from Prosopis juliflora against Phytopathogenic Fungi

The ability of Bacillus subtilis, strain ALICA to produce three mycolytic enzymes (chitinase, β-1,3-glucanase, and protease), was carried out by the chemical standard methods. Bacillus subtilis ALICA was screened based on their antifungal activity in dual plate assay and cell-free culture filtrate (25%) against five different phytopathogenic fungi Alternaria alternata, Macrophomina sp., Colletotrichum gloeosporioides, Botrytis cinerea, and Sclerotium rolfesii. The B. subtilis ALICA detected positive for chitinase, β-1,3-glucanase and protease enzymes. Fungal growth inhibition by both strain ALICA and its cell-free culture filtrate ranged from 51.36% to 86.3% and 38.43% to 68.6%, respectively. Moreover, hyphal morphological changes like damage, broken, swelling, distortions abnormal morphology were observed. Genes expression of protease, β-1,3-glucanase, and lipopeptides (subtilosin and subtilisin) were confirmed their presence in the supernatant of strain ALICA. Our findings indicated that strain ALICA provided a broad spectrum of antifungal activities against various phytopathogenic fungi and may be a potential effective alternative to chemical fungicides.

Lipopeptide production by Bacillus subtilis R1 and its possible applications

Abstract The possible application of a bacterial strain - Bacillus subtilis R1, isolated from an oil contaminated desert site in India, as biocontrol agent and its biosurfactant in microbial enhanced oil recovery are discussed. The biosurfactant production in minimal medium was carried out at different temperatures and salt concentrations, where it produced an efficient biosurfactant at 30-45 °C and in presence of up to 7% salt. It significantly reduced the surface tension from 66 ± 1.25 mN/m to 29 ± 0.85 mN/m within 24 h. In order to enhance the biosurfactant production, random mutagenesis of B. subtilis R1 was performed using chemical mutagen - ethyl methanesulfonate. Majority of the isolated 42 mutants showed biosurfactant production, but the difference was statistically insignificant as compared with parent strain R1. Therefore none of the mutants were selected for further study, and only parent strain R1 was studied. The biosurfactant was quite stable under harsh conditions for up to 10 days. The biosurfactant was extracted and characterized as similar to the lipopeptide group - surfactins and fengycin. The crude oil displacement experiments using biosurfactant broth in sand pack glass columns showed 33 ± 1.25% additional oil recovery. The strain also showed inhibition of various plant pathogenic fungi on potato dextrose agar medium.

Antifungal activities of tacrolimus in combination with antifungal agents against fluconazole-susceptible and fluconazole-resistant Trichosporon asahii isolates

ABSTRACT The antifungal activity of tacrolimus in combination with antifungal agents against different fungal species has been previously reported. Here we report the in vitro interactions between tacrolimus and amphotericin B, fluconazole, itraconazole, and caspofungin against 30 clinical isolates of both fluconazole-susceptible and fluconazole-resistant Trichosporon asahii. For these analyses, we used the broth microdilution method based on the M27-A3 technique and checkerboard microdilution method. Tacrolimus showed no activity against T. asahii strains (minimal inhibitory concentrations, MICs > 64.0 µg mL−1). However, a larger synergistic interaction was observed by the combinations tacrolimus + amphotericin B (96.67%) and tacrolimus + caspofungin (73.33%) against fluconazole-susceptible isolates. Combinations with azole antifungal agents resulted in low rates of synergism for this group (fluconazole + tacrolimus = 40% and itraconazole + tacrolimus = 10%). Antagonistic interactions were not observed. For the fluconazole-resistant T. asahii group, all tested combinations showed indifferent interactions. The synergism showed against fluconazole-susceptible T. asahii isolates suggests that the potential antifungal activity of tacrolimus deserves in vivo experimental investigation, notably, the combination of tacrolimus with amphotericin B or caspofungin.

Eficacia y seguridad de la caspofungina en pediatría: revisión sistemática y metaanálisis / Efficacy and safety of caspofungin in children: systematic review and meta-analysis

Las infecciones fúngicas invasivas son una importante causa de morbimortalidad en pediatría. La caspofungina es una equinocandina utilizada como alternativa en la prevención y/o tratamiento de ciertas infecciones fúngicas invasivas en niños, aunque con poca evidencia sobre su eficacia y seguridad en comparación con el tratamiento habitual. Objetivos. Evaluar la eficacia y seguridad de la caspofungina comparada con otros antifúngicos en la prevención y/o tratamiento de infecciones fúngicas invasivas en pediatría. Material y métodos. La estrategia de búsqueda inicial tuvo como objetivo identificar estudios controlados aleatorizados de aceptable calidad metodológica (escala de Jadad > 3) mediante la palabra clave "caspofungin" realizados en pacientes de entre los 0 y los 18 años. Resultados. Solo 3 publicaciones cumplieron los criterios de inclusión. De ellas, 2 fueron en población pediátrica y una en neonatal. No se documentó una mayor incidencia de efectos adversos para la caspofungina y su eficacia no se diferenció de otros antifúngicos (RR típico 1,47; IC 95%: 0,78-2,79). Conclusiones. Esta revisión sistemática sugiere que la caspofungina podría considerarse como una alternativa para su indicación en pediatría en la prevención y tratamiento de las infecciones fúngicas invasivas. Sin embargo, dado el pequeño número de publicaciones existentes, se requieren más estudios para alcanzar conclusiones definitivas.

Invasive fungal infections are a significant cause of morbidity and mortality in children. Caspofungin is an echinocandin used as an alternative treatment in the prevention and/or treatment of certain invasive fungal infections in children, although compared to the standard treatment there is little evidence on its efficacy and safety. Objectives. To evaluate the efficacy and safety of caspofungin compared with other antifungal drugs for the prevention and/or treatment of invasive fungal infections in children. Material and methods. The objective of the initial search strategy was to identify randomized controlled studies of acceptable methodological quality (Jadad scale >3), through the key word "caspofungin", conducted in patients with an age range from 0 to 18 years old. Results. Only 3 publications met the inclusion criteria. Two of them were studies conducted in children and one in newborn infants. A higher incidence of adverse events was not documented for caspofungin and its efficacy was not different from that of other antifungal drugs (typical RR 1.47; CI 95%: 0.78-2.79). Conclusions. This systematic review suggests that caspofungin could be considered as an alternative drug in children for the prevention and treatment of invasive fungal infections. However, given the small number of existing publications, more studies are required to reach definite conclusions.

Breeding of high-producing LI-F lipopeptide Paenibacillus polymyxa by protoplast fusion and differential expression analysis of fusion strains / 生物工程学报

Auxotrophic strains of N1-37 (Phe-) and N2-27 (His-), screened from mutations of Paenibacillus polymyxa JSa-9 previously, were used as the parent strains to screen high-producing LI-F antibacterial lipopeptide fusion strain through protoplast fusion with polyethylene glycol as a promote agent. Fusion strain F5-15 was obtained. Then the product of LI-F antibacterial lipopeptide was quantified by HPLC, and the difference of expression of the key genes of lipopeptide synthase between wild strain JSa-9 and the fusion strain was analyzed by real-time PCR. LI-F antibacterial lipopeptide yield of the fusion strain F5-15 was 3.1-fold of the original strain JSa9's, and the expression levels of the target genes were 10.48, 2.48, 2.1 and 11.8 fold of the initial strain JSa-9, respectively.

Characterization and properties of the biosurfactant produced by Candida lipolytica UCP 0988

Background: Biotechnological processes are costly, especially for the production of biosurfactants. The successful production of a biosurfactant is dependent on the development of processes using low cost raw materials. Considering the importance of the characteristics of a biosurfactant to facilitate its industrial application, the properties of the biosurfactant produced by Candida lipolytica through previously optimized medium have been established. Results: The yeast was grown for 72 h to determine the kinetics of growth and production. The surface tension of the cell-free broth was reduced from 55 to 25 mN/m. The yield of biosurfactant was 8.0 g/l with a CMC of 0.03%. The biosurfactant was characterized as an anionic lipopeptide composed of 50% protein, 20% lipids, and 8% of carbohydrates. Conclusions: The isolated biosurfactant showed no toxicity against different vegetable seeds: Brassica oleracea, Solanum gilo and Lactuca sativa L. and the micro-crustacean Artemia salina. The properties of the biosurfactant produced suggest its potential application in industries that require the use of effective compounds at low cost.

Caspofungin versus liposomal amphotericin B for treatment of invasive fungal infections or febrile neutropenia / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Nowadays, there are published trials in regards to the comparison of caspofungin with liposomal amphotericin B (L-AmB). However, these studies have a modest sample size and convey inconclusive results. The aim of this study was to review the efficacy and safety of caspofungin for the treatment of invasive fungal infections (IFIs), compared with L-AmB.</p><p><b>METHODS</b>Electronic databases (up to July 31, 2013) PubMed and Embase databases, the Cochrane Library, and Google Scholar were searched to identify relevant trials of caspofungin and L-AmB. Analyses of efficacy and adverse outcomes were performed by relative risks (RRs) and 95% confidence intervals (CIs). Heterogeneity was assessed by χ(2)-test and the I(2)-statistic.</p><p><b>RESULTS</b>Three trials were included in this meta-analysis with 1249 modified intention-to-treat (MITT) patients. The results showed that caspofungin produced equal efficacy in favorable overall response (RR = 1.02, 95% CI 0.88-1.18; P = 0.81) and mortality rate (RR = 1.53, 95% CI 0.38-6.27, P = 0.55), safer in clinical adverse events (RR = 0.20, 95% CI 0.08-0.54; P = 0.001), laboratory adverse events (RR = 0.69, 95% CI 0. 57-0.84; P = 0.0002), and discontinuation rate (RR = 0.26, 95% CI 0.08-0.83, P = 0.02), compared with L-AmB in the treatment of patients with IFIs.</p><p><b>CONCLUSION</b>Based on the results of this meta-analysis, it would appear that caspofungin was measured to have equal efficacy in clinical outcomes and safer in terms of adverse events.</p>

Fermentation of Bacillus subtilis ge25 strain and preliminary study on its antagonistic substances / 中国中药杂志

Panax ginseng is one of the most important traditional Chinese herbal medicine, soil borne diseases influenced the yield and quality severely. In our previous work, endophytic Bacillus subtilis ge25 strain was isolated from ginseng root, and which showed significant antagonistic activity against several most destructive ginseng phytopathogens. In the present work, crude protein and lipopeptid extracts were prepared from LB and Landy supernate by salting out, acid precipitation methods respectively. The antagonistic activity of crude extracts and stability to temperature and protease digestion were examined by ginseng phytopathogen Alternaria panax. Results showed that, the antagonistic activity of crude protein extracts from LB culture was complete and partially lost when treated by high temperature and proteinase K. However, crude lipopeptid from Landy culture showed significant stabile antagonistic activity to them. Acid-hydrolyzation and TLC-bioautography analysis showed, that the crude lipopeptide contained at least one cyclic lipopeptide. In consideration of the stability and perfect antagonistic activity of ge25, further researches will promote the biocontrol of ginseng diseases in the field.

Influence of TLR2 and TLR4 agonists on migration of human bone marrow mesenchymal stem cells / 中国实验血液学杂志

This study was aimed to investigate the influence of TLR2 and TLR4 agonists on the migration and adhesion activity of human bone marrow-derived mesenchymal stem cells (MSC) and to clarify the underlying mechanisms. The expression of TLR2 and TLR4 on MSC was detected by flow cytometry. The effects of TLR2 agonist (PAM3CSK4) and TLR2 agonist (LPS) on MSC migration and adhesion ability were evaluated with chemotaxis and adhesion test. The results indicated that expressive levels of TLR2 and TLR4 on surface of human bone marrow MSC were (24.5 ± 3.2)% and (91.3 ± 5.2)% respectively. Compared with the control group, the migration activity of MSC toward SDF-1 was decreased significantly in PAM3CSK4 group, while the adhesion activity of MSC was promoted by PAM3CSK4 exposure. However, both the migration activity toward SDF-1 and the adhesion activity of MSC were not changed significantly in LPS-treated group. Further, it was found that PAM3CSK4 did not affect the expressive level of CXCR4 on MSC, however, it could inhibit the spontaneous migration of MSC in dose dependent manner. It is concluded that activation of TLR2 can decrease the migration ability of MSC, which may associate with the decreased spontaneous migration ability and the increased adhesion activity of MSC.

Bacillus sp. BS061 Suppresses Gray Mold and Powdery Mildew through the Secretion of Different Bioactive Substances

A Bacillus sp. BS061 significantly reduced disease incidence of gray mold and powdery mildew. To identify the active principle, the culture filtrate was partitioned between butanol and water. The antifungal activity against B. cinerea was evident in the butanol-soluble portion, and active substances were identified as cyclic lipopeptides, iturin A series, by nuclear magnetic resonance spectrometry (NMR) and mass analysis. Interestingly, antifungal activity against powdery mildew was observed in the water-soluble portion, suggesting that cyclic lipopeptides have no responsibility to suppress powdery mildew. This finding reveals that biocontrol agents of Bacillus origin suppress gray mold and powdery mildew through the secretion of different bioactive substances.

Optimization of surfactin production by Bacillus subtilis ATCC 6633 in a miniaturized bioreactor

In recent years, biosurfactants due to wide applications in chemical, petroleum, food and pharmaceutical industries, have been widely considered by researchers. Biosurfactants are produced by a series of microorganisms, so it is important to screen culture medium and operating conditions in miniaturized bioreactors prior to scaling up to large bioreactors.In this study, using a kind of miniaturized bioreactor called ventilation flask, optimal production conditions, including filling volume and shaking frequency to produce a surfactin-type biosurfactant by Bacillus subtilis ATCC 6633, were examined. Moreover, the effect of oxygen transfer rate [OTR] on the surfactin production was investigated according to Amoabediny and Buchs model. The results indicated that the maximum biomass and biosurfactant yield which obtained under optimal conditions [filling volume of 15 mL and shaking frequency of 300 rpm] were evaluated 0.3 g/L/h and 0.0485 g/L/h, respectively. Also, at the same conditions, the amount of surface tension decreased from 60.5 mN/m to 31.7 mN/m and the maximum oxygen transfer rate [OTR[max]] obtained as 0.01 mol/L/h