Oil palm empty fruit bunches (OPEFB) is one of the largest types of solid waste produced by palm oil mills (POM). Each processing of 1 ton of fresh fruit bunches (FFB) produces 220–230 kg of empty fruit bunches (EFB). One of the attempts to overcome the accumulation of EFB is by composting. The main obstacle in composting OPEFB is the process of overhauling, it takes 6-12 months because OPEFB contains 33.02% cellulose, 22.05% hemicellulose and 35.08% lignin. One of the efforts to speed up the composting is using biological treatment by adding microorganisms such as cellulolytic bacteria which are capable in producing cellulase enzymes. The reseach was carried out experimentally using a non-factorial completely randomized design (CRD) consisting of eight treatments, namely B0 (control), B1   (Bacillus tequilensis Strain RA 1402), B2 (Bacillus subtilis Strain C17), B3 (Bacillus subtilis Strain SKUASIS) , B4 (Bacillus subtilis Strain DSM 10), B5 (Bacillus subtilis Strain K43), B6 (Pseudomonas aeruginosa Strain KUJM) and B7 (Combined Isolates). The parameters observed were physical properties of compost, weight loss of compost and total of compost microb population. The resultof the research showed that cellulolytic bacteria isolates had a significant effect on weight loss of compost, pH. The combined isolates (B7) is the best treatment in increasing compost material weight, pH. The treatment B7 has the best ability in producing high quality compost which is under the SNI Compost Quality Standard: 19?7030?2004.     Keyword: Oil palm empty bunches, cellulolytic bacteria, composting.

White oyster mushroom (Pleurotus ostreatus) requires a source of nutrients for growth and development. The provision of NPK fertilizer aims to increase the source of media nutrients so that the results obtained are better in quantity and quality. Growth regulators can stimulate the relatively long growth of oyster mushroom mycelium. Growth regulators contain hormones that can support growth rates. One alternative natural growth regulator that can be used is coconut water. The research was carried out at the oyster mushroom kumbung at Pekanbaru, using a completely randomized design, consisting of 2 factors and three replications. The first factor was NPK fertilizer consisting of 4 levels (0, 7.5, 10, 12.5) g per baglog. The second factor was coconut water consisting of 4 levels (0, 3, 6, 9) ml per baglog. Data were analyzed using Analysis of Variance and further tested using DNMRT level 5%. The results showed that adding 10 g of NPK fertilizer and 6 ml of coconut water per baglog was a better dose for the number of fruit bodies, fresh fruit body weight, fruit cap diameter, fruit stalk length, and biological efficiency.