Isolasi dan Identifikasi Jamur Penghasil Protease Serupa Renin

Abstract

Keju merupakan produk olahan fermentasi susu yang dikonsumsi karena mengandung protein yang tinggi. Pembuatan keju diawali dengan proses penggumpalan susu. Penggumpalan tersebut terjadi akibat dari pemotongan ikatan kappa kasein pada ikatan phe 105 – met 106 oleh renin, protease pada agen penggumpal (rennet). Namun alternatif lain muncul dikalangan industri, yakni menggunakan enzim protease ekstraselluler mikroba yang salah satunya jamur, karena jamur mudah diisolasi serta melimpah di berbagai kondisi alam. Mikroba lokal berpotensi untuk dikembangkan menjadi alternatif dalam mendukung industri pembuatan keju. Maka dari itu, eksplorasi lokal diperlukan untuk mendapatkan isolat jamur penghasil protease serupa renin dan berpotensi dalam menggumpalkan susu. Penelitian ini bertujuan mendapatkan isolat jamur lokal yang memiliki potensi menghasilkan protease mirip renin serta menentukan karakter dasar dari isolat jamur yang didapatkan. Penelitian ini dilakukan dengan mengisolasi sampel dari tanah peternakan sapi perah di Desa Batur, Getasan, Jawa Tengah, menyeleksi isolat penghasil protease serupa dengan renin menggunakan metode SDS-PAGE, dan identifikasi isolat secara morfologi. Sampel tanah diambil dari area lahan peternakan sapi perah secara langsung dan rutin terlimpasi sisa air susu sapi yang banyak mengandung protein sehingga harapannya mendapatkan jamur lokal penghasil protease serupa renin. Penelitian ini mendapatkan 10 isolat yang potensial sebagai penghasil protease, yang ditunjukkan dengan adanya zona bening pada media selektif termodifikasi dengan kombinasi susu skim dan PDA. Isolat dengan kode JR 1 dan JR 3 memiliki zona terang terluas dan proteasenya mampu menggumpalkan susu skim. Pengujian pada SDS-PAGE menunjukkan bahwa protease dari semua isolat menghasilkan produk hidrolisis protein susu skim yang berbeda dengan rennet komersial. Hasil ini mengindikasikan bahwa protease dari 10 isolat yang diperoleh memiliki spesifisitas pemotongan pada protein skim milk yang berbeda dengan rennet komersial sebagai rujukan. Hasil identifikasi secara morfologi dengan metode slide culture menunjukkan bahwa 10 isolat tersebut diduga berasal dari 3 jenis genus yang sama: yakni Aspergillus, Penicillium dan Mucor.

Cheese is a processed product from fermented milk and it is widely consumed as it contains high protein. Making cheese begin with process of milk coagulation. The coagulation is due to the result of the split of kappa casein bond in phe105- met106 and this split is caused by renin, a protease in clotting agent (rennet). In recent development of cheese production, there is another alternative way to produce cheese. It uses microbial extracellular protease enzymes such as fungi. Fungi are easy to be grown and it is naturally abundant. Microbes have the potential to be grown and used as an alternative way to making cheese. Therefore, it is important to explore local resources to produce fungi isolates as protease producers similar to renin and it can coagulate milk. This research was conducted to source and produce local fungi isolates which have a potential to produce protease similar to renin as well as to determine the primary characteristics of the fungi isolates. This study was conducted by isolating soil samples taken from dairy farms in Batur village, Getasan, Central Java. Isolates as protease producer similar to renin were selected by using SDS-PAGE, and was identified morphologically. The soil samples were taken directly from dairy farms and the area is often saturated by the milk remaining which contains protein. Thus, it is hoped that fungi producing renin-like protease can be acquired. This research was able to produce ten isolates which have a potential to be protease producers as it is shown by yellow zones on the modified selective media with skim milk and PDA combination. Isolates with codes JR1 and JR3 have the biggest bright zones and their proteases are able to coagulate skim milk. The examination on SDS-PAGE shows those proteases from all isolates produce skim millk protein hydrolysis products which are different from commercial rennet. The result shows that protease from the acquired 10 isolates have the specifications of detachment in skim milk protein which are different from commercial rennet as a reference. The result of fungi isolates identification by slide culture method shows that the 10 isolates are suspected from 3 different, but similar genus. They are Aspergillus, Penicillium, and Mucor.