Komagataella phaffii (formerly known as Pichia pastoris) has become an increasingly important microorganism for recombinant protein production. This yeast species has gained high interest in an industrial setting for the production of a wide range of proteins, including enzymes and biopharmaceuticals. During the last decades, relevant bioprocess progress has been achieved in order to increase recombinant protein productivity and to reduce production costs. More recently, the improvement of cell features and performance has also been considered for this aim, and promising strategies with a direct and substantial impact on protein productivity have been reported. In this review, cell engineering approaches including metabolic engineering and energy supply, transcription factor modulation, and manipulation of routes involved in folding and secretion of recombinant protein are discussed. A lack of studies performed at the higher-scale bioreactor involving optimisation of cultivation parameters is also evidenced, which highlights new research aims to be considered.

Chagas disease, caused by the protozoan parasiteTrypanosoma cruzi, has no effective treatment available. On the other hand, microalgae are aquatic organisms that constitute an interesting reservoir of biologically active metabolites. Moreover, some species of green and red algae present anti-protozoan activity. Our aim was to study the antiparasitic effects of aqueous, methanolic and ethanolic extracts from different microalgae. Our results show that the methanolic extracts of S. obliquus and T. suecica as well as the ethanolic extracts of C. reinhardtii and T. suecica present trypanocidal activity on the infective extracellular trypomastigotes and intracellular amastigotes. In addition, the ethanolic extract of C. reinhardtii potentiates the activity of the conventional antichagasic drug nifurtimox. In order to identify some potential compounds with trypanocidal activity, we performed a phytochemical screening analyzing the presence of phenolic compounds, pigments and terpenoids. The different microalgae extracts, particularly the ethanolic extract ofC. reinhardtii, are promising potential candidates for the development of future natural antichagasic drugs.

Nosocomial infections caused by bacteria are one of the main public health problems. Moreover, the resistance to antibiotics by these bacteria makes it necessary to find new treatments to fight them.Objective. To evaluate the antibacterial activity ofLuma apiculata(DC.) Burret extracts on bacteria of clinical importance.Materials and Methods. In this study, extracts were obtained at room temperature by successive extraction ofL. apiculataleaves, flowers, and branches and treated separately with solvents of ascending polarity (i.e., hexane, methylene dichloride, ethyl acetate, ethanol, methanol, and water) to extract the compounds depending on their polarity. Then, the extract’s antibacterial activity was tested againstStaphylococcus aureus,Staphylococcus epidermidis,Staphylococcus saprophyticus,Enterococcussp,Acinetobacter baumanii,Pseudomonas aeruginosa, andEscherichia coli.Results. The hexane extract ofL. apiculataleaves resulted to be active against all bacteria tested. Among them,S. aureusshowed to be the more susceptible, showing a minimum inhibitory concentration (MIC) of 120 μg/ml. In addition, a growth curve was performed, and colonies were counted. A decrease in bacterial growth was observed when the hexane extract ofL. apiculataleaves was added. Besides, the hexane extracts ofL. apiculataflowers resulted to be active against all Gram-positive tested bacteria. However, at higher concentrations, this extract resulted inactive for the Gram-negative bacteria tested. The hexane extract ofL. apiculatabranches resulted to be inactive in all cases. The extracts obtained treating separately leaves, flowers, or branches with solvents of major polarity than the hexane in a successive extraction of ascending polarity methodology resulted also to be inactive as an antimicrobial against all bacteria tested.Discussion/Conclusion. The hexane extract ofL. apiculataleaves showed the lower MIC againstS. aureuswhen compared with extracts obtained from other parts of the plant. The growth curve and the colonies count suggest a bacteriostatic activity of theL. apiculataleaves extract againstStaphylococcus aureus.