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Microalgae is one of the prominent sources for biodiesel production. Cultivation of a specific microalgae strain (chlorella sp.) in wastewater using a pilot-scale open pond raceway was studied. Daily measurement of the raceway parameters such as pH, optical density and dissolved oxygen indicated that growth phase prolonged for 15 days and pH of the culture stayed on 9.4 for the most part of the period. Dissloved oxygen initially decreased sharply and then rised to approximately 8 mg/l during cultivation. The results showed that municipal wastewater is a suitable culture medium for algal cultivation and is comparable with synthetic cultures in terms of main parameters of growth.

The biological function of proteins is largely determined by their individual component domains, which are segments within the protein sequence that are self-contained and spatially arranged. These can be catalytic or structural, and define a number of different features of proteins such as their enzymatic activity, interactions with other proteins, sugars or lipids, and determine the cellular localization of the proteins that contain them. A number of intracellular three-dimensionally-arranged domains, such as Src-homology (SH) or Pleckstrin-homology (PH) domains, define the nature of protein interactions with other components of the cell, and enable them to interact with their substrates or binding partners. The specificity of interactions that is given by the domain is unique to its protein. Similarly, the extracellular part of most membrane-bound or secreted proteins of eukaryotic cells is also organized in semi-autonomously-arranged blocks that potentially confer multiple diverse functions to a particular protein. These domains have been classified and grouped into protein superfamilies depending on the similarity they have with domains of prototypical proteins, for example immunoglobulin, fibronectin or C-type lectin domains. Members of these groups are believed to be homologous and to have arisen by divergent evolution from a common ancestor. Many membrane-bound or extracellular proteins are comprised of several domains of the same type, but it is not uncommon to find mosaic proteins containing domains from different superfamilies. The scavenger receptor cysteine-rich (SRCR) superfamily comprises a group of proteins that contain one or multiple domains structurally similar to the membrane distal domain of the type I scavenger receptor expressed by human macrophages (Freeman et al., 1990). Proteins classified as belonging to this superfamily may contain other types of domains additionally to the dominant SRCR modules, such as EGF, CUB, LCCL, or other domains. In mammals, SRCR proteins are typically expressed in cells of the immune system (Resnick et al., 1994), although some members can be also expressed in non-immune cells and organs, including liver, kidney, placenta, stomach, brain and heart (Sarrias et al., 2004). Group A domaincontaining SRCR proteins are present in phyla from the most primitive metazoan to

Bioactive peptides play critical roles in regulating most biological processes in animals, and they have considerable biological, medical and industrial importance. Peptides belonging to the same family are often characterized by a typical short sequence motif (pattern) that is highly functionally preserved among the family members. In this chapter, we design a pattern search method to facilitate the detection of such conserved motifs. First, all known bioactive peptides annotated in Uniprot are collected and classified, and the program Pratt is used to search these unaligned peptide sequences in each family for conserved patterns. The obtained patterns are then refined by taking into account the information on amino acids at important functional sites collected from literature, and are further tested by scanning them against all the Uniprot proteins. The diagnostic power of the patterns is demonstrated by the fact that, while the false positive is kept to zero to ensure that the signatures are exclusive to peptides and their precursors, nearly 94% of all known peptide family members accommodate one or several of the identified patterns. In total, we brought to light 155 novel peptide patterns in addition to the 56 established ones in the PROSITE database. All the patterns represent 110 peptide families; among which 55 are not characterized by PROSITE and 12 are also dismissed by other existing motif databases, such as Pfam. Using the newly uncovered peptide patterns as a search tool, we predicted 95 hypothetical proteins as putative peptides or peptide precursors.

The recently developed field of systems biology creates a new framework for understanding the molecular basis of physiological or pathophysiological states of cells. Screening modalities that can be used on single cells are needed to study cellular systems biology. The recent development of cellular microarrays has provided a method for the complex molecular analysis of living, single cells (Chen & Davies, 2006). Unlike other highthroughput systems, such as gene expression profiling microarrays or protein microarrays, cellular microarrays use a printed pattern of geographically distinct spots to probe living cells, rather than cell lysates, or other non-viable samples. Among the most powerful tools to assay gene function on a genome-wide scale in the physiological context of intact living cells are fluorescence microscopy and related imaging techniques (Pepperkok & Ellenberg, 2006). To enable these techniques to be applied to functional genomics experiments, fluorescence microscopy is making the transition to a quantitative and high-throughput technology.