**4.3 Oil palm frond**

The most plentiful residue of oil palm trees is oil palm frond (OPF), which accounts for up to 70% of total palm waste [15]. According to recent studies, OPF is an excellent source of renewable carbon and lignocellulosic content for cultivating a variety of species to produce essential biochemical products such as pigments, enzymes, and succinic acid. **Table 5** summaries the biochemical product by various microorganisms using OPF as a substrate. When fermentation conditions such as temperature, pH, and oxygen level, are allowed, a variety of organisms may produce a variety of products. As shown in **Table 2**, OPF contains a high percentage of cellulose (40–56%) and hemicellulose (16–38%), making it ideal for microbial growth.

#### **4.4 Palm oil mill effluent**

The liquid waste released during the palm oil extraction process is known as palm oil mill effluent (POME). POME is one of the world's most polluting wastewaters due to its high organic matter content and it is 100 times more polluted than municipal sewage [30]. Each tonne of palm oil produces approximately 5.5–7.5 tonnes of POME [31, 32]. While, about more than 50 million m3 of POME is generated globally each year [33].

POME is a viscous, dense brownish liquid with significant quantities of colloidal matter that is acidic (pH 3.7 to 4.5) [34]. POME also has a high chemical and biochemical oxygen demand (COD and BOD), ranging between 69,500 and 89,591 mg/L and 34,771 and 48,300 mg/L, respectively [34]. The physicochemical


#### **Table 5.**

*Biochemical production from different organisms using OPF as substrate.*

properties of POME are shown in **Table 6**. A large amount of amino acids, inorganic nutrients (Na, K, Ca, Mg, Mn, Fe, Zn, Cu, Co, and Cd), small fibers with nitrogenous compounds, free organic acids, and carbohydrates are also found in POME [37]. Organic matter such as lignin (4700 ppm), phenolics (5800 ppm), pectin (3400 ppm), and carotene (8 ppm) are also present [34]. This suggests that POME is an appropriate source for biological treatment.

POME's physicochemical properties can vary depending on local and process factors (climate, organisms, pre-treatment, and oil extraction process, for


#### **Table 6.**

*Physico-chemical characteristics of POME.*

*Lignocellulosic of Oil Palm Biomass to Chemical Product via Fermentation DOI: http://dx.doi.org/10.5772/intechopen.99312*


#### **Table 7.**

*Biochemical production from different organisms using POME as substrate.*

example) [34]. Other biochemical products may be produced using the treatment technique. **Table 7** summarizes the different fermentation processes on various biochemical products using POME as a substrate.
