Pengaruh Radiasi Microwave dan Perlakuan Asam pada Batubara Peringkat Rendah terhadap Perolehan Biosolubilisasi Menggunakan Neurospora intermedia

Abstrak. Biosolubilisasi batubara peringkat rendahmerupakan teknologi yang menjanjikan untuk mendapatkan bahan bakar cair yang ramah lingkungan. Biosolubilisasi batubara peringkat rendah dapat dilakukan dengan menggunakan mikroorganisme seperti Neurospora intermedia yang mampu menghasilkan enzim-enzim pensolubilisasi. Mekanisme biosolubilisasibatubaraterjadikarenaadsorpsienzim-enzim tersebutkepermukaan partikel batubara, sehingga proses perlakuan awal batubara perlu dilakukan untuk memudahkan proses adsorpsi enzim.Penelitian ini dilakukan untuk mengkaji pengaruh perlakuan awal partikel batubara peringkat rendah terhadap struktur batubara dan perolehan biosolubilisasi. Pengaruh perlakuan awal tersebut dikaji dengan membandingkan biosolubilisasi menggunakan partikel batubara tanpa perlakuan awal (B1), perlakuan fisik dengan memberikan radiasi microwave 511 Watt selama 5 menit (B2), perlakuan kimiawi dengan merendam partikel batubara dalam HNO3 8 M selama 48 jam (B3), serta perlakuan kombinasi radiasi microwave selama 5 menit dan HNO3 dengan konsentrasi 2, 4, 6, dan 8 M selama 48 jam (B4, B5, B6, dan B7). Partikel batubara B1 memiliki rentang diameter mesopori sebesar 33,97 Å, sedangkan partikel batubara yang telah mengalami perlakuan awal mengalami peningkatan diameter pori namun masih dalam rentang mesopori. Luas permukaan persatuan massa dan volume pori yang tertinggi diperoleh dari perlakuan B3, masing-masing adalah 44,39 m2/g dan 0,09 cc/g. Hasil analisis proksimat dan ultimat menunjukkan bahwa perlakuan asam dapat mengurangi kandungan karbon terikat. Secara kualitatif dapat terlihat bahwa biosolubilisasi batubara B1, B2, B4, dan B5 tidak terjadi dengan baik, sehingga tidak terdapat cairan hitam sebagai hasil batubara yang tersolubilisasi, sedangkan biosolubilisasi batubara B3, B6, dan B7 menghasilkan cairan hitam sejak hari pertama. Secara kuantitatif, biosolubilisasi batubara peringkat rendah menggunakan perlakuan B3 menghasilkan konsentrasi asam humat dan persentase biosolubilisasi yang tertinggi, masing-masing yaitu 186,1 mmol/L dan 67,8%. Kata kunci: biosolubilisasi batubara, HNO3, Neurospora intermedia, radiasi microwave. Abstract. Effect of Microwave Radiation and Acid Treatment on Low Grade Coal on Biosolubilization Acquisition Using Neurospora intermedia. Bio-solubilization of low rank coal is a promising technology to obtain environmentally friendly liquid fuel. Bio-solubilization can be carried out using microorganism, such as Neurospora intermedia, which is capable to produce solubilizing enzymes. Mechanism of coal bio-solubilization occurs due to enzymes adsorption onto surface of coal, so that the low rank coal pre-treatment is needed to easy enzyme adsorption. This research examines the effects of low rank coal pre-treatment towards coal structure and bio-solubilization yields. The effects of the pre-treatment were studied by comparing the bio-solubilization using coal with the following specification: without treatment (B1), physical pre-treatment of 511 Watt microwave radiation for 5 minutes (B2), chemical pre-treatment using 8 M HNO3 for 48 hours (B3), and pre-treatment with a combination of microwave radiation for 5 minutes and acid treatment using various HNO3 concentration of 2, 4, 6, and 8 M for 48 hours (B4, B5, B6, and B7, respectively). Coal particle of B1 had mesopore diameter range of 33.97 Å, while coal particle with pre-treatment have increased pore diameter, but are still in range of mesopore. The coal obtained by B3 process has the highest specific surface area and pore volume, which were 44.39 m2/g and 0.99 cc/g, respectively. The proximate and ultimate analyses showed that acid treatment reduced fixed carbon contain. Coal bio-solubilization of B1, B2, B4, and B5 by qualitative could not be solubilized and there was no black liquid as a result of solubilized coal, meanwhile, B3, B6, and B7 were solubilized easily since the first day. Bio-solubilization of chemically pre-treatment low rank coal, B3, resulted in the highest humic acid concentration and bio-solubilization percentage i.e. 186.1 mmol/L and 67.8%, respectively. Keywords: coal bio-solubilization, HNO3, microwave radiation, Neurospora intermedia.

Phân lập và nhận diện các dòng nấm mốc hiện diện trên vỏ bưởi Da Xanh và bưởi Năm Roi được trồng ở Đồng bằng sông Cửu Long

Nghiên cứu được thực hiện với mục đích phân lập và nhận diện các dòng nấm mốc hiện diện trên bề mặt hai loại bưởi thường trồng ở Đồng bằng sông Cửu Long là bưởi Da xanh và bưởi Năm Roi. Kết quả cho thấy cả hai loại bưởi đều có tần suất phân lập nấm cao, với 8 dòng nấm được tìm thấy đối với mỗi giống bưởi. Các dòng nấm phân lập được xác định đặc tính hình thái và định danh theo phương pháp sinh học phân tử, sử dụng cặp mồi ITS1 và ITS4. Từ vỏ bưởi Da Xanh, các dòng nấm phân lập được là Aspergillus brunneoviolaceus, A. aculeatus, A. carbonarius, Trichoderma asperellum và Neurospora intermedia. Tương tự, việc xác định bằng giải trình tự gen trên đoạn ITS cho thấy 8 dòng phân lập được chọn lọc từ bưởi Năm Roi có mức độ đồng hình 98 ÷ 100% với A. niger, A. assiutensis, A. aculeatus, N. intermedia, Schizophyllum commune và Penicillium sp. Việc nhận diện các dòng nấm có trên vỏ bưởi là bước đầu tiên để đề xuất điều kiện tiền xử lý và bảo quản sau thu hoạch phù hợp, giúp kéo dài thời gian bảo quản bưởi tươi.

Fungi Burger from Stale Bread? A Case Study on Perceptions of a Novel Protein-Rich Food Product Made from an Edible Fungus

The current study aims to assess how a novel fungi product made from the filamentous fungus Neurospora intermedia, cultivated on bread residuals, is perceived using questionnaires. Participants were asked to rate characteristic attributes of a fungi burger patty and state their preference when comparing it to Quorn and hamburger patties. The data were analyzed to assess whether gender or age was statistically associated with preference profiles. Neither age nor gender was associated with the preference profiles regarding the comparison of burger patties. Except for age and bitterness, age and gender were also not associated with the preference profiles regarding the sensory characteristics of the fungi burger patty. Most of the participants liked the characteristics of the fungi burger patty. The results indicate that fungi products from waste can become accepted products when information dissemination targets environmental benefits. Moreover, to be commercially accepted, the chewiness and bitterness of the product should be improved. Other improvements should target the overall taste in order to cater to people who prefer meat-based protein sources.

Bioethanol Production from Sugarcane Bagasse Using Neurospora intermedia in an Airlift Bioreactor

Bagasse as solid waste in sugarcane industry can be utilized as one of the potential raw materials in the bioprocess industry. This research aims to investigate the conversion of bagasse to bioethanol using simultaneous saccharification and fermentation in an airlift bioreactor. Neurospora intermedia was used as a biological agent that carried out the saccharification and fermentation of sugarcane bagasse simultaneously for bioethanol production. Cell morphology of N. intermedia in the form of pellet was required to provide free movement in the axial flow of airlift bioreactor. The medium pH strongly affects the morphological shape of N. intermedia. Therefore, the formation of good pellets of inoculum was observed under acidic conditions, i.e. pH 3.0 – 3.5. The effect of the initial concentration of nutrient on the inoculum growth was also investigated. Inoculums cultured in potato dextrose broth (PDB) medium with a half the strength of the common nutrient concentration of PDB qualitatively indicated good growth in terms of the size and density of cells. The inoculums with good morphological form were fed into the airlift bioreactor, which already contained a liquid medium with initial pH of 3.5 and also contained pre-treated bagasse. In experiments using the airlift bioreactor, the pre-treated bagasse was added to various nutrient concentrations of the PDB infusion medium. The highest bioethanol production from bagasse was monitored in the medium culture of half strength PDB infusion. The yield of bioethanol obtained from total sugarcane bagasse and PDB in an air lift bioreactor achieved approximately 40%, which has an infusion medium with a half-strength PDB and initial pH of 3.0. ©2020. CBIORE-IJRED. All rights reserved

Amylase and Xylanase from Edible Fungus Neurospora intermedia: Production and Characterization

Integrated enzyme production in the biorefinery can significantly reduce the cost of the entire process. The purpose of the present study is to evaluate the production of two hydrolyzing enzymes (amylase and xylanase) by an edible fungus used in the biorefinery, Neurospora intermedia. The enzyme production was explored through submerged fermentation of synthetic media and a wheat-based waste stream (thin stillage and wheat bran). The influence of a nitrogen source on N. intermedia was investigated and a combination of NaNO3 and yeast extract has been identified as the best nitrogen source for extracellular enzyme production. N. intermedia enzymes showed maximum activity at 65 °C and pH around 5. Under these conditions, the maximum velocity of amylase and xylanase for starch and xylan hydrolysis was found to be 3.25 U mL−1 and 14.77 U mL−1, respectively. Cultivation of N. intermedia in thin stillage and wheat bran medium resulted in relatively high amylase (8.86 ± 0.41 U mL−1, 4.68 ± 0.23) and xylanase (5.48 ± 0.21, 2.58 ± 0.07 U mL−1) production, respectively, which makes this fungus promising for enzyme production through a wheat-based biorefinery.