## 2 Production of Lipases  
### Microbial Sources of Lipases  
Lipases are found in microorganisms, including bacteria, yeasts and filamentous fungi. Compared to animal sources, including pancreatic lipases, and plant lipases, for instance from _Cara papaya_ and seeds, microbial lipases have been more exploited due to the necessity of simple and inexpensive culture media, practical handling, possibility of scale-up cultivations, and availability of various tools for genetic and protein engineering. The existence of profound knowledge regarding their genetics and physiology (especially for model organisms such as _E. coli_, _K. phaffii_ and _Saccharomyces cerevisiae_) makes them important candidates for lipase production [40; 41].  
Most lipases investigated are from bacterial sources, such as enzymes from the genera _Bacillus, Geobacillus, Pseudomonas, Streptomyces, Burkholderia, Chromobacterium_, _Alchromobacter_, _Arthobacter_ and _Alcaligenes_[41; 42]. Among them, _Bacillus_ lipases are the most explored enzymes, having stable activity at high temperatures in a broad range of pH conditions, besides their tolerance to organic solvents [41].  
From an industrial perspective, however, lipases produced by yeasts and filamentous fungi are more attractive as they can be obtained in high concentrations and have unique properties regarding thermal stability and substrate specificity [34; 40]. Lipases from _Candida_, _Geotrichum_, _Trichosporon_, _Yarrowia_, _Aspergillus_, _Penicillium_, _Rhizopus_, _Rhizomucor_ and _Thermomyces_ stand out as the most important enzymes of fungal origin [42; 43]. Some of them have been optimized for better industrial properties and are available commercially, such as the lipase B (CALB) from _Candida antarctica_ (Novozym\({}^{\circledR}\) 435 and NS 88011), Lipozyme\({}^{\circledR}\) TL IM from _Thermomyces tanuginosus_ (Novozymes, Copenhagen, Denmark), Novozym\({}^{\circledR}\) 40,086 from _Rhizomucor miehei_, and Lipase FE-01 from _A. oryzae_ (ASA Spezialenzyme GmbH, Wolfenbuttel, Germany) [44].  
Microorganisms that grow in environments with extreme pH, salinity and temperature conditions are also important sources of lipases with industrial potential. Unfortunately, they may not be easy to propagate at laboratory conditions and their lipases may therefore be more difficult to recruit for human use. Extremophile bacteria, such as thermophiles and psychrophiles, found in hot springs, deep sea sediments and extremely cold spots, such as Antarctica, can survive in those hostile environments and produce diverse lipases with unique tolerance properties. The lipases from extremophiles have been the subject of many studies [44; 45; 46], and, according to the Genomes OnLine Database, there are currently 1364 metagenomics studies of environmental samples covering more than 10,000 strains ([[https://gold.jgi.doe.gov/](https://gold.jgi.doe.gov/)]([https://gold.jgi.doe.gov/](https://gold.jgi.doe.gov/))). Those data bring evidence of the great potential of the uncultured microbial communities as sources for prospecting new lipases with catalytic activity for a broad array of substrates, as well as being pH and temperature tolerant. We envision that codon optimized lipase genes from these sources will be systematically screened in heterologous hosts to deliver novel industrially important lipases in the future.