**4.1 Fungi**

Three fungal classes get the most attention in SSF:


Many fungal strains can produce various types of pectinase enzymes. The produced metabolites by *Aspergillus niger* are safely used and involved in GRAS (Generally Regarded As Safe), so that it is the most broadly strain used in industries [61]. *A. niger* can produce various pectinases involving esterase, PGL, and PMGL. Currently, the enzymes of *A. niger* are used in wine industries and fruit juice [62]. It is reported that almost all the fungi pectinases have acidic nature, so it is applicable to work only in acidic conditions [63]. However, the pectinase production by *Aspergillus* strains produced higher via SSF than in SmF [64]. Wherever the most commercial pectinases are produced from fungal sources in the industry by *Trichoderma* and *Aspergillus* [65].

#### **4.2 Yeast**

In 1951, Luh and phaff produced for the first time endoPG from yeast [66]. They identified four species of pectolytic yeasts: *Saccharomyces fragilis, Torulopsis kefir, Candida pseudotropicalis* (all later renamed as *Kluyveromyces marxianus*), and *Saccharomyces thermantitonum* (reclassified as *Saccharomyces cerevisiae*) [67]. Pectolytic yeasts can be producing PG, lyase, or esterase, depending on the pH, temperature conditions, and substrate availability. For example, *Candida*, *Saccharomyces, and Kluyveromyces* can be producing PG (mainly endo-Polygalacturonase), whereas *Rhodotorula* can be releasing both pectin esterase and PG [68].

*S. cerevisiae* is considered the most experienced yeast. Initially, it had believed that *S. cerevisiae* is free of pectolytic enzymes [69]. However, some strains have been shown since then reduction ability for pectin [70]. PG Activity is the main pectolytic activity in *S. cerevisiae* and was reported in several strains [71]. It is noted that most pectolytic activities have been described in the indigenous yeasts [72]. These yeasts have been mainly discovered during different fermentation [73] or through the clarification and pressing of concentrated juices [74].

#### **4.3 Bacteria**

Chawanit Sittidilokratna *et al*. [75] performed screening of pectinase-producing bacteria and the effectiveness evaluation for bio-pulping. At first, Pectinolytic bacteria were screened from six identified and 118 unknown isolates. Twelve strains gave positive results, including three of *Erwinia carotovora subsp*. *carotovora*, two of *Erwinia chrysanthemi* and seven of *Bacillus* sp. Crude pectinases were prepared from the selected strains. Then, investigate the activity of three types of pectinase (PG, pectate lyase, and pectin lyase). The results showed the highest PG production from *Bacillus* sp. strain N10 and *E. chrysanthemi* strain N05. N10 was isolated from paper mulberry bark, while N05 was isolated from onion [76]**.** *Bacillus licheniformis* KIBGE-IB21 was isolated from rotten vegetables and produce pectinase at certain

*The Microbial Degradation for Pectin DOI: http://dx.doi.org/10.5772/intechopen.100247*

conditions [77]**.** However, the commonly used bacteria for pectinase production are *Aeromonas caviae, B. licheniformis, and Lactobacillus* [32]*.*
