Biotechnology and Bioprocess Engineering 2008, 13: 571-576 DOI/10.1007/s12257-008-0014-7 Effects of Inoculum Concentration, Temperature, and Carbon Sources on Tannase Production during Solid State Fermentation of Cashew Apple Bagasse = Tigressa H. S. Rodrigues 1 , Gustavo A. S. Pinto 2 , and Luciana R. B. Gonçalves 1 *= 1 Universidade Federal do Ceará - Departamento de Engenharia Química, Campus do Pici, Bloco 709 - 60455-760, Fortaleza, CE - Brazil 2 Embrapa Agroindústria Tropical, Rua Dra. Sara Mesquita, 2270, Planalto do Pici - 60511-110, Fortaleza, CE – Brazil= Abstract In this study, the optimization of tannase production by solid state fermentation was investigated using cashew apple ba- gasse (CAB), an inexpensive residue produced by the cashew apple agroindustry, as a substrate. To accomplish this, CAB was enriched with 2.5% (w/w) tannic acid and 2.5% (w/w) ammonium sulphate and then moistened with water (60 mL/100 g of dry CAB). The influence of inoculum concentration (10 4 to 10 7 spores/g), temperature (20, 25, 30, and 35°C) and several additional carbon sources (glucose, starch, sucrose, maltose, analytical grade glycerol, and glycerol produced during bio- diesel production) on enzyme production by ^ëéÉêÖáääìë= çêóò~É was then evaluated. Supplementation with maltose and glycerol inhibited tannase synthesis, which resulted in lower enzyme activity. Starch and sucrose supplementation increased enzyme production, but decreased the enzyme productivity. The maximum tannase activity (4.63 units/g of dry substrate) was obtained at 30°C, using 10 7 spores/g and 1.0% (w/v) sucrose as an additional carbon source. © KSBB hÉóïçêÇëW=Å~ëÜÉï=~ééäÉ=Ä~Ö~ëëÉI=ëçäáÇ=ëí~íÉ=ÑÉêãÉåí~íáçåI= Aspergillus oryzaeI=í~åå~ëÉ= = = = = INTRODUCTION Solid state fermentation (SSF) is a bioprocess in which microorganisms are grown on solid substances in the ab- sence or near absence of free water [1]. In general, SSF takes place under low water/high solids conditions [2]. Two types of substrates are used in SSF, those that are used by the mi- croorganisms as the carbon and energy source, and those that only support the fermentation process [3]. Due to its low cost and effectiveness, SSF is often the system of choice for con- verting agro industrial residues to fermented foods, enzymes, and other extracellular metabolites such as organic acids and flavour compounds [2]. The cashew apple is a pseudofruit native to Brazil that is primarily grown in the North and Northeast regions of Brazil, where the cashew agroindustry plays a substantial role in the local economy. Cashew apples are hard, pear-shaped, small, *Corresponding author Tel: +55-85-3366-9611 Fax: +55-85-3366-9610 e-mail: lrg@ufc.br nonclimacteric fruit that occur in three colours: yellow, or- ange, and red. The primary product of the cashew apple is the cashew nut, which is well known around the world. The edible portion, which comprises 90% of the fruit, is a pseudofruit rich in vitamin C, flavour, and aroma. However, the industrially processed pseudofruit products are consumed by the local market and do not play an important role in the state or national economy [4-7]. When the pseudofruit is industrially processed for the pro- duction of juice, 40% (w/w) of the fruit remains as bagasse. This bagasse is not used for human consumption and is gen- erally discarded. However, due to its composition (Table 1), cashew apple bagasse (CAB) represents an interesting and inexpensive (less than US$ 0.50/kg) substrate for several applications, including the production of microbial enzymes by solid state fermentation (SSF) [8-10]. Tannase (tannin acyl hydrolase, E.C. 3.1.1.20) catalyzes the hydrolysis of bonds present in the molecules of tannins and gallic acid esters [11]. Tannase is applied commercially in the food and drink industries, as well as in the production of pharmaceutically important compounds such as gallic acid.