Application of artificial neural networks for enhancing Aspergillus flavipes lipase synthesis for green biodiesel production.

Biodiesel is a sustainable, and renewable alternative to fossil fuels that can be produced from various biological sources with the aid of lipases. This study developed a simple and novel fungal system for lipase biosynthesis to be used for catalyzing the oily residuals into biodiesel, employing the artificial neural network (ANN), and semi-solid-state fermentation (SSSF). Nigella sativa was selected among agro-industrial oily residuals as a substrate for lipase biosynthesis by Aspergillus flavipes MH47297. The effect of cultural humidity (X1), the surfactant; Brij 35 (X2), and inoculum density (X3) on lipase biosynthesis were researched based on the matrix of Box-Behnken design (BBD). The ANN together with a new fungal candidate and SSSF were then applied for the first time to model the biosynthesis process of lipase. The optimum predicted cultural conditions varied according to the model. The optimum predicted conditions were estimated separately by BBD (X1 = 5.8 ml water/g, X2 = 46.6 µl/g, and X3 = 62156610 spore/g) and ANN (X1 = 5.4 ml water/g, X2 = 54.2 µl/g, and X3 = 100000000 spore/g) models. Based on the modeling process, the response of lipase was calculated to be 214.95 (BBD) and 217.72 U (ANN), which revealed high consistency with the experimental lipase yield (209.13 ± 3.27 U for BBD, and 218 ± 2.01 U for ANN). Despite both models showing high accuracy, ANN was more accurate and surpassed the BBD model. Gas chromatography analysis showed that lipase successfully converted corn oil to biodiesel (29.5 mg/l).

Rhizopus oryzae AM16; a new hyperactive L-asparaginase producer: Semi solid-state production and anticancer activity of the partially purified protein.

The demand for L-asparaginase is predicted to increase several fold in the future due to its potential clinical applications in the treatment of lymphoid system malignancies and leukemia. Thus identifying suitable sources of production should be considered high priority. Fungi are valuable organisms as they are able to convert what would be considered 'useless' materials into materials that have potential value. The present study provides a proof of concept of production of a new hyperactive L-asparaginase producer (Rhizopus oryzae AM16), which was successfully isolated and sequentially optimized using a semi solid-state fermentation method with a simple and cheap medium produced from wheat bran (WB). The fungus was able to produce an appreciable amount of the enzyme (2,875.9 U) after 8 days of incubation under 85.7% moisture, in the presence of magnesium nitrate (5.0 mg N/mg nitrogen per gram of dry WB) at pH 5.8. Testing the anticancer activity confirmed the ability of the resultant enzyme to inhibit the growth of various types of cancer cells (HepG2, MCF-7, HCT and A549). The IC50 values of the dialyzed enzyme were lower than that of the crude product. Thus, this newly identified and purified L-asparaginase may be a promising anticancer drug.

Terretonin O: a new meroterpenoid from Aspergillus terreus.

Terretonin O (1), a new meroterpenoid, was isolated individually from both methanolic extracts of thermophilic Aspergillus terreus TM8 and marine Aspergillus terreus LGO13. The recently reported terretonins M (2) and N (3) were further isolated from the fungus LGO13 along with nine known compounds, terrelumamide A (4), terrein (5), methyl-3,4,5-trimethoxyl-2-[2-(nicotinamide)benzamido] benzoate (6), butyrolactones I-III (7-9), aspulvinone O (10), ergosterol, ergost-4-ene-3-one and methyl linoleate. Structure of terretonin O (1) was established on the bases of HRESIMS, 1D and 2D NMR spectra and comparison with its analogues in literatures. The relative stereochemistry of 1 was assigned on the basis of NOESY spectra and comparison with reported configuration of its congener compounds 2 and 3. The antimicrobial and cytotoxic activities of the fungal extracts and obtained compounds were assayed using a set of microorganisms, and cervix carcinoma cell line (KB-3-1), respectively. Isolation and taxonomical characterization of the producing strains are reported.

Secondary metabolites from Penicillium sp. 8PKH isolated from deteriorated rice straws.

In the search for bioactive secondary metabolites from terrestrial fungi, four compounds, namely, 3-methyl-3H-quinazolin-4-one (1), aurantiomide C (2), 3-O-methylviridicatin (3), and dehydrocyclopeptine (4), were isolated from Penicillium sp. 8PKH, fungal strain, isolated from deteriorated rice straws. The structures of the isolated compounds were identified by extensive NMR and mass analyses and comparison with literature data. This is the first report of the structure of 3-methyl-3H-quinazolin-4-one (1) with full NMR spectral data having been previously identified by GC-MS from Piper beetle. Analysis of the non-polar fractions of the strain extract by GC-MS revealed the presence of additional eight compounds: methyl-hexadecanoate, methyl linoleate, methyl-9 (Z)-octadecenoate, methyl-octadecanoate, cis-9-oxabicyclo (6.1.0) nonane, 9,12-octadecadienal (9E,12E), ethyl-(E)-9-octadecenoate, and 3-buten-2-ol. The isolated compounds were evaluated for their antimicrobial and cytotoxic activities and exhibited little or no inhibitory activities against the test strains. The taxonomical characterisation and fermentation of the fungal strain were reported as well.

Diverse polyketides and alkaloids from Penicillium sp. KHMM: structural elucidation, biological and molecular docking studies.

As a continuation of our earlier research concerning the investigation of microbial bioactive secondary metabolites from the terrestrial Penicillium sp.KH Link 1809 isolate KHMM, the fungus was re-cultivated on a large scale to explore its bioactive compounds intensively. Fifteen compounds, including seven alkaloids (1-7), one sesquiterpene (8), an acetylenic system (9), two sterols, and sphengolipid, were identified. Their structures were established on the bases of extensive one- and two-dimensional nuclear magnetic resonance and mass measurements, and by comparison with literature data. The antimicrobial activity of the fungal extract and the corresponding compounds were studied using a panel of pathogenic microorganisms, and their in vitro cytotoxicity against the human cervix carcinoma cell line (KB-3-1) was reported as well. The molecular docking of the isolated compounds showed promising affinities for the alkaloidal compounds 4-6 towards α, ß tubulins.