en بیوتکنولوژی میکروبی Microbial Biotechnology مقاله پژوهشی Original Research Article <p style="text-align: justify;"><span style="font-size:16px;"><span style="font-family:Times New Roman;"><b><span style="background:#1f497d"><span style="color:white"><span style="letter-spacing:-.1pt">Background and Aim:</span></span></span></b><span style="color:black">&nbsp;</span><span style="line-height:150%"><span style="color:black"><span style="line-height:150%">Melanin is a ubiquitous, dark, polymeric pigment found naturally in plants, animals and microbes. It has several industrial, biotechnological, and pharmaceutical applications. The study aimed to verify the presence, type, and quantity of melanin produced by eight species belonging to the <i>Aspergillus (A.)</i> section <i>Nigri</i>: <i>A. awamori</i>, <i>A. brasiliensis</i>, <i>A. costaricaensis</i>, <i>A. luchuensis</i>, <i>A. piperis</i>, <i>A. niger</i>, <i>A. tubingensis</i> and <i>A. welwitschiae</i> We also determined the biosynthetic pathway (either 3, 4-dihydroxyphenylalanine (DHN) or 1,8-dihydroxynaphthalene (DOPA)) responsible for melanin synthesis in these species.</span></span></span><br> <b><span style="background:#1f497d"><span style="color:white"><span style="letter-spacing:-.1pt">Materials and Methods:</span></span></span></b><span style="color:black"> </span><span style="line-height:150%"><span style="color:black"><span style="line-height:150%">Soil samples were collected from seven locations within Basrah Province. Species identification was performed through sequencing of ITS region and &beta;-tubulin gene. The isolates were cultured on CDA and L-tyrosine PDA, and incubated for 7, 14 and 21 days for melanin extraction. Qualitative and quantitative characterizations of melanin were done using UV&ndash;Vis spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The biosynthetic pathway of melanin was investigated by applying the pathway inhibitors; kojic acid and difenoconazole.</span></span></span><span style="color:black"> </span><br> <b><span style="background:#1f497d"><span style="color:white"><span style="letter-spacing:-.1pt">Results:</span></span></span></b><span style="color:black"> </span><span style="line-height:150%"><span style="color:black"><span style="line-height:150%">The results indicated that <i>A. niger </i>produced 1.9 gr of melanin after 3 weeks on L-tyrosine PDA. DHN pathway was identified in <i>A. niger</i> and <i>A. brasiliensis</i>, whereas the DOPA pathway was active across all tested species.</span></span></span><br> <b><span style="background:#1f497d"><span style="color:white"><span style="letter-spacing:-.1pt">Conclusion:</span></span></span></b><span style="color:black">&nbsp;</span><span style="line-height:150%"><span style="color:black"><span style="line-height:150%">The study revealed interspecies differences in the type and quantity of melanin produced among <i>A.</i> section <i>Nigri</i> isolates.</span></span></span></span></span></p> Aspergillus Section Nigri, DHN-melanin, DOPA-melanin, Difenoconazole, Kojic Acid 403 421 http://ijmm.ir/browse.php?a_code=A-10-2996-1&slc_lang=en&sid=1 Shaymaa S. Raheem shaymaa.raheem@uobasrah.edu.iq 100319475328460033912 100319475328460033912 Yes Department of Ecology, College of Science, University of Basrah, Basrah, Iraq Mohanad K. Mohammed Ameen mohanad.ameen@uobasrah.edu.iq 100319475328460033913 100319475328460033913 No Department of Biology, College of Science, University of Basrah, Basrah, Iraq Mustafa A. AL-Dossary mustafa.najem@uobasrah.edu.iq 100319475328460033914 100319475328460033914 No Department of Ecology, College of Science, University of Basrah, Basrah, Iraq