Kitosan merupakan polimer alami bermuatan positif yang dapat diaplikasikan bidang farmasi sebagai penghantar obat. Akan tetapi, kitosan komersil memiliki berat molekul besar dan derajat deasetilasi yang rendah, sehingga aplikasinya terbatas akibat kelarutannya yang rendah pada air. Penelitian ini bertujuan untuk menentukan pengaruh metode depolimerisasi dua kelas kitosan yang beredar dipasaran terhadap karakteristiknya. Jenis kitosan yang digunakan yaitu pharmaceutical grade dan food grade untuk menghasilkan oligokitosan. Metode depolimerisasi kitosan yang digunakan adalah iradiasi sinar UV-C (75 menit), hidrolisis enzim papain (15 g/L selama 16 jam, 40oC dan pH 5) serta kombinasi UV dan enzim. Hasil penelitian menunjukkan bahwa grade kitosan dan metode depolimerisasi mempengaruhi karakteristik kitosan depolimerisasi yang dihasilkan. Ketiga metode yang digunakan pada kitosan pharmaceutical grade menghasilkan oligokitosan yang dapat larut langsung pada air dengan pH netral dengan rendemen >62%, derajat putih 99,33%, berat molekul 85%. Kitosan food grade yang melalui depolimerisasi dengan metode berbeda belum dapat larut dalam air dengan pH netral. Kitosan food grade yang melalui depolimerisasi kombinasi UV+enzim memiliki kualitas derajat deasetilasi yang identik dengan kitosan pharmaceutical grade.

Kukis merupakan makanan ringan bergluten yang digemari banyak kalangan, dengan kandungan serat dan protein yang rendah. Peningkatan kualitas kukis dengan mengganti terigu menjadi tepung sagu, penambahan Spirulina dan rumput laut merah Eucheuma cottonii dapat mengurangi kadar gluten, meningkatkan kandungan protein dan serat, serta meningkatkan daya tarik. Tujuan penelitian ini menentukan pengaruh penambahan E. cottonii terhadap mutu kukis sagu Spirulina berdasarkan karakteristik kimia, mikrob dan daya terima. Kukis dibuat dengan mencampurkan bahan menggunakan metode creaming (margarin dan gula), whisking (penambahan kuning telur) dan all in (penambahan tepung sagu, Spirulina dan rumput laut). Kukis diuji proksimat, total plate count (TPC), aktivitas air (aw), senyawa bioaktif, angka kecukupan gizi (AKG) dan uji hedonik. Hasil analisis kimia kukis menunjukkan kandungan air dan serat kasar meningkat sebesar 4,32% dan 0,56%. Hasil TPC dalam batas aman berdasarkan SNI (<105). Kukis tergolong makanan kering dengan aw 0,5 dan mengandung senyawa aktif flavonoid, steroid dan saponin. Hasil perhitungan AKG, konsumsi sebanyak 15 g kukis menghasilkan energi total 76 kkal. Hasil penilaian hedonik menunjukkan kukis dengan penambahan E. cottonii dan Spirulina dapat diterima. Secara keseluruhan, penambahan rumput laut dan Spirulina pada kukis meningkatkan gizi dan dapat diterima oleh panelis.

Ulva lactuca is a green seaweed that has three times faster growth than other types of seaweed and high sulfate polysaccharide content that can be used for biological activities. Deep Eutectic Solvents (DES) emerged as an alternative to extracting ulvan due to its biodegradable, environmentally friendly, and harmless nature. This study aims to determine the type and concentration of DES that can produce the best ulvan extract characteristics based on yield, FTIR, and viscosity analysis as well as moisture and sulfate content tests. The stages of research carried out include preparation and characteristics of raw materials, DES synthesis, extraction, and further analysis and tests. Different types and concentrations of DES affect the results of the analysis. The test results showed the highest ulvan yield found in the 30% choline chloride-urea DES type treatment (KKU30), while the sulfate content and viscosity values were found in the 30% choline chloride-glycerol treatment (KKG30). The ulvan functional group in the 30% choline chloride-glycerol treatment (KKG30) showed absorption band results similar to HCl treatment.

Fishery Ulva lactuca is a potential green seaweed species that causes green tides and has not been utilized. U. lactuca has the potency to attract cellulolytic bacteria due to its high carbohydrate content. U. lactuca is commonly found on the southern seacoast of Java Island, one of which is Ujung Genteng Beach, Sukabumi, Indonesia. In this research, we investigated the potential of cellulolytic bacteria from U. lactuca. Sources of bacteria are coming from the environment, the surface of the seaweed, and inside the seaweed (endophytes). To be able to determine the origin of the potential bacteria, the total plate count (TPC) was calculated with treatment without washing, washing with distilled water, and washing with a combination of distilled water and alcohol. From these bacteria, cellulolytic activity was tested using CMC media and morphological characterization. The most bacteria were found in the treatment without washing, as much as 7.48 Log Cfu/ml. The washing process reduced the TPC to 5.88 and 5.7 Log Cfu/ml in the treatment of washing with distilled water and washing with a combination of distilled water and alcohol, so that endophytic bacteria were obtained. The bacterial isolate with the highest cellulolytic potential was UW 1(1)1 5A1 from the non-washing treatment with a cellulolytic index of 2.25. These Gram-positive bacteria were in the form of filamentous lobates with a matte cream color with cocci-shaped cells. Meanwhile, the potential endophytic bacteria were Gram-positive coccus bacteria UW 3(1)1.2 with a cellulolytic index of 0.85. Both isolates have the potency to degrade cellulose.