Carotenoids represent a class of diverse compounds naturally present in bacteria, fungi, algae and plants. Animals cannot synthesize carotenoids de novo and need to obtain them from diet. Carotenoids serve a variety of functions such as antioxidants, colorants and precursors of vitamins. Chemical synthesis of carotenoids is challenging and costly. Extraction from plants is also laborious and often limited by the availability of the sources. There exists a demand for microbial production of carotenoids by fermentation. This paper reviews recent patents on microbial biotechnology to illustrate advances in microbial carotenoid production. Patents on composition of matters such as new strains, new genes or gene clusters, and improved genes, as well as methods on production of carotenoids to increase titer and purity are discussed.