Kefir is a fermented milk product that has the typical flavours (acids and alcohol) and its processed by a number of microbes which include lactic acid bacteria (LAB) and yeasts.The aims of this study were to know the character of the population of lactic acid bacteria (LAB), a population of yeasts, and chemical characters among others total acid, pH and alcohol levels in kefir milk with inoculum ragi tape. The population of LAB and the population of yeast were calculated with the method of calculation of Total Plate Count. The levels of total acid titration method were determined by the acid. Acidity was measured using a pH meter and alcohol levels were determined by the method of Conway Micro Diffusion. The results showed that the number of LAB has increased to 24 hour fermentations of 9.01 log cells/ml (1,1x109 cells/ml), then the number of cells did not change much until the fermentation time was 48 hours and 72 hours of fermentation on the decline of 8.07 log cells /ml (1,2x108 cells/ml) while the yeast experiences increased from 6 hours to 24 hours, then the amount of yeast did not much change from the 24 to 72 hours of the highest number of yeasts during fermentation 48 hours an amount of 6.12 log cells /ml (1,3x106 cells/ml) and the amount of yeasts did not decline at the time of 72 hours. Total acid continued to experience increased with the number of 0.38-1.24%, pH continued to decline from 6,47-4.27 and alcohol levels continued to experience increased with the number of 0.05-0.38% b/v. Keywords: Inoculum, Kefir Milk, Lactic Acid Bacteria, Ragi Tape, Yeast

Abstract. Rosa E, Ekowati CN, Handayani TT, Ikhsanudin A, Apriliani F, Arifiyanto A. 2020. Characterization of entomopathogenic fungi as a natural biological control of American cockroaches (Periplaneta americana). Biodiversitas 21: 5276-5282. Eradicating cockroaches using chemical insecticides produces residues that contaminate the environment and promote insect resistance. Biological control has become an option for controlling cockroaches. The use of entomopathogenic fungi is one of them. The aim of this study was to obtain a fungal isolate that was effective at killing cockroaches. The result of entomopathogenic fungi isolation from cockroaches obtained 4 isolates, IK1, IK2, IK3 isolates were included in the Aspergillus genus while IK4 was Penicillium. Extracellular enzymes serve as screening materials for biocontrol candidates. IK1 and IK3 isolates showed higher chitinase activity than the other two isolates. The highest mortality of Periplaneta americana at nymphs stage was 60% achieved by the treatment of Aspergillus sp. IK3 with a concentration of 109 conidia/ mL. In adult stage cockroach the mortality was increased to 86%.

AbstrakPenelitian ini bertujuan untuk mengetahui daya antibakteri yang dihasilkan oleh isolat bakteri asam laktat dari kefir susu sapi dan susu kedelai terhadap Escherichia coli. Penelitian ini dilakukan dalam empat tahapan yaitu isolasi dan identifikasi BAL kefir, produksi zat antibakteri dari isolat, menguji daya hambat isolat antibakteri BAL terhadap Escherichia coli. Hasil penelitian menunjukan Keenam Isolat bakteri asam laktat dari kefir susu kedelai dan kefir susu sapi mampu menghambat pertumbuhan Escherichia coli dalam kondisi asam dan netral. Dalam kondisi asam luas zona hambat KE1-KE3 berturut-turut adalah 3,51; 2,93; 2,66 dan SA1-SA3 adalah 1,83; 2,46; 2,46. Dalam kondisi netral zona hambat KE1-KE3 berturut-turut adalah 1,59; 2,33; 1,99 dan SA1-SA2 adalah 1,49; 2,49; 2,39. AbstractThis study aimed to determine the antibacterial power produced by isolates of lactic acid bacteria from kefir of cow's milk and soy milk on Escherichia coli. This research was conducted in four stages, namely isolation and identification of kefir BAL, antibacterial substance production from isolates, testing the inhibition of BAL antibacterial isolates against Escherichia coli. The results showed that the sixth lactic acid bacterial isolate from soybean kefir and cow's milk kefir was able to inhibit the growth of Escherichia coli in acidic and neutral conditions. In acidic conditions, the KE1-KE3 inhibition zone is 3.51; 2.93; 2,83; 2.46; 2.46. In the neutral condition of the respectively 1.59; 2.33; 1,49; 2.49; 2.39. PENDAHULUANKefir merupakan produk fermentasi dari susu hewani atau susu kedelai menggunakan starter berupa butir atau biji kefir (kefir grain/kefir granule ) yang terdiri dari berbagai kumpulan bakteri asam laktat seperti Lactobacilli, Streptococcus sp., Lactococcus, dan beberapa jenis ragi/khamir nonpatogen. Bakteri asam laktat menghasilkan senyawa-

Mannose and mannooligosaccharide acted as prebiotic that consumed by probiotic bacteria. Mannanase were the second most important enzymes for the hydrolysis of hemicelluloses, beside xylanase. The objective research was to obtain eminent strains of Bacillus sp. in mannan degradation which can potentially be a probiotic candidate. The study employed a completely randomized design using four concentration levels repeated six times. Halotolerant Bacteria were isolated from mangrove ecosystem at Hanura beach, Teluk Pandan, Pesawaran District in Lampung Province. They are grown on the sea water complete agar media. Mannan degradation isolates were then characterized to determine their character with a variety of tests, including resistance to pH, salt, and metal ions, pathogenicity, and determination of mannanase production duration. Thirty strains are found to grow at 3-6% salt content, and 9 of them have mannanolytic activity. They grow optimally at pH 7-10. Seven isolates were proven to be positively hydrolyzed blood agar in the pathogenicity test. The addition of Iron (III) Chloride increased the enzyme activity by 11.12% in IBK3 isolates at 96 hours of cultivation period which was 0.05 UmL-1. It acted as cofactors of enzymatic reactions. Strains Bacillus sp., were able to degrade mannan substrate. It quantified using Index of mannanolytic. Strain IBK3 has the highest index of mannanolytic activity as much as 10.74. Their ability to grow in salt media indicated that they were halotolerant. They were more likely to live at base rather than acid habitat. Only IBK3 and ID2K1 showed non-pathogenic isolates. Only FeCl 3 addition has proven to rise up enzymatic activity.

This study aimed to determine the effect of pH on the production of antibacterial by lactic acid bacteria. This study uses a completely randomized design factorial 3X 5 (3 X 5 treatment of bacterial isolates pH) with three replications. The first factor consisted of pH 4, pH 5, pH 6, pH 7, pH 8, and PENDAHULUANSalah satu sumber bakteri asam laktat (BAL) diperoleh dari usus itik. Pada umumnya, BAL digunakan sebagai probiotik, khususnya genus Lactobacillus dan Bifdobacterium yang merupakan bagian dari flora normal pada saluran pencernaan (Sujaya et al., 2008). Keberadaan BAL mampu bertahan di dalam variasi pH pada saluran pencernaan itik (Tillman et al., 1989). Pada tembolok itik memiliki pH sekitar pH 6,3, pH di lambung antara 1 -2, pH di ileum antara 7 dan 8, pH di proventrikulus 2 -4, dan pH di ventrikulus 2,6 (Anggorodi, 1984). Bakteri asam laktat mampu memproduksi bakteriosin untuk menghambat atau membunuh bakteri yang bersifat selektif hanya terhadap beberapa strain patogen. Salah satu produksi antibakteri dipengaruhi oleh faktor lingkungan yaitu pH, umur bakteri, waktu inkubasi, suhu dan lain -lain. PH optimum diperlukan untuk produksi antibakteri karena pH sangat berpengaruh dalam pembentukan bakteriosin optimum pada pH 5 dan 6

No abstract

Lalat rumah (M. domestica) merupakan vektor mekanik berbagai penyakit oleh mikroba patogen antara lain Salmonella penyebab demam tifoid, Shigella penyebab disentri, dan E. coli penyebab diare. Pengendalian M. domestica umumnya menggunakan insektisida sintetis, namun menimbulkan resistensi dan berdampak buruk bagi lingkungan. Oleh karena itu, perlu dilakukan pengendalian alternatif berupa pengendalian biologi menggunakan isolat jamur entomopatogen sebagai bioinsektisida. Penelitian ini diawali dengan isolasi jamur entomopatogen menggunakan metode moist chamber dengan larva M. domestica sebagai serangga pancingan. Jamur yang tumbuh pada larva dikultur dan dimurnikan pada media PDA lalu diidentifikasi. Identifikasi dilakukan melalui pengamatan makroskopis meliputi warna dan diameter koloni dan pengamatan mikroskopis meliputi struktur konidia, konidiofor, hifa, vesikula, fialid, dan sel kaki. Hasil isolasi dan identifikasi diperoleh lima jenis isolat yaitu Aspergillus sp. 1, Aspergillus sp. 2, Geotrichum sp., Penicillium sp., dan Aspergillus sp. 3.

The aim of this study is to know the viability of Lactic Acid Bacteria isolates on ration and combination of ration  with molasses. This study used a mixture of lactic acid bacteria isolates from the duck intestine (B4, B7, B8). The third bacterial isolates were inoculated on two different treatment media,  on rantion media (R1), and combination of rantion + molasses (R2). The study was arranged by randomized block design (RAK) 6x2 factorial treatment pattern. Factor A is the incubation time of 0 hours, 2 hours, 4 hours, 6 hours, 8 hours and 10 hours. Factor B is two types of growing media of lactic acid bacteria, is ransum media, and  combination of ransum + molasses. Each treatment was repeated 3 times. This research uses pour plate method with the calculation of the colony using colony counter. Data  analyzed descriptively. The results showed that the addition of 1.6% molasses (R2) maintains the number of LAB population at 4th hour with the cell number 7,36 x 105 CFU / g. While on the ration medium (R1) can maintain the amount of LAB at 6th hour  with the cell number of 6,20 x 105 CFU / g. LAB  population viability on feed medium with addition of molases 1.6% (R2) has increased on storage time at 4th hour with cell number 7,36 x 105 CFU / g, while on feed medium (R1) decreased cell count 6,08 x 105 CFU / g. Keywords: Viability, Lactic Acid Bacteria, Ransum, Molase.