Seaweed extract biostimulants are among the best modern sustainable biological plant growth promoters. They have been proven to eliminate plant diseases and abiotic stresses, leading to maximizing yields. Additionally, they have been listed as environmentally friendly biofertilizers. The focus of the present research is the use of a commercial seaweed biostimulant as an eco-friendly product (formally named True Algae Max (TAM). During the 2017 and 2018 seasons, five treatments of various NPK:TAM ratios were applied via regular fertigation, namely a conventional treatment of 100% NPK (C0) alongside combinations of 25%, 50%, 75%, and 100% (C25, C50, C75, and C100) of TAM, to evaluate the effectiveness of its bioactive compounds on enhancing growth, yield, and NPK content of cucumber (Cucumis sativus) under greenhouse conditions. TAM is rich in phytochemical compounds, such as milbemycin oxime, rhodopin, nonadecane, and 5-silaspiro [4.4]nona-1,3,6,8-tetraene,3,8-bis(diethylboryl)-2,7-diethyl-1,4,6,9-tetraphenyl-. Promising measured parameter outcomes showed the potentiality of applying TAM with and without mixes of ordinary NPK application. TAM could increase cucumber yield due to improving chemical and physical features related to immunity, productivity, and stress defense. In conclusion, it is better to avoid applying mineral fertilizers, considering also that the organic agricultural and welfare sectors could shortly depend on such biotechnological tools and use them to fulfill global food demands for improved sustainability.

To achieve strong, successful and commercial aqua-biotechnological microalgae applications, screening, isolation, molecular identification, and physiological characterizations are needed. In the current study, a native cyanobacteria strain Arthrospira platensis NIOF17/003 was isolated from the surface water of El-Khadra Lake, a saline-alkaline lake located in Wadi El-Natrun, Egypt. The cyanobacterium was phylogenetically identified by 16S rRNA molecular marker and deposited in the GenBank database (accession number MW396472). The late exponential phase of A. platensis NIOF17/003 was reached at the 8th day of growth using Zarrouk medium, with a recorded dry weight (DW) of 0.845 g L−1. The isolated strain showed 52% of protein, 14% of carbohydrate, biomass productivity of 143.83 mg L−1 day−1, 8.5% of lipid, and lipid productivity of 14.37 mg L−1 day−1. In general, the values of cetane number, iodine value, cold filter plugging point (52.9, 85.5 g I2/100 g oil, and −2.2 °C, respectively) of the isolated fatty acid methyl esters are in accordance with those suggested by international standards. Besides, applying algal-free lipid (FL) as biodiesel byproduct in the production of rotifer (Brachionus plicatilis) revealed that a 0.6 g L−1 FL significantly increased the rotifer population females carrying eggs, confirming that FL can be used efficiently for B. plicatilis production. The current study concluded that the new isolate A. platensis NIOF17/003 is a promising strain for double sustainable use in biodiesel production and aquaculture feed.

To assess the genetic diversity of Nile tilapia Oreochromis niloticus, a total of 250 ¢sh from ¢ve Egyptian populations were genotyped using six microsatellite markers. Heterozygosity and Wright's F-statistics (F IS , F ST , and F IT ) were calculated to determine the genetic variation within and between these populations. Observed heterozygosities were in the range of 0.4 (Burullus) to 0.96 (Qena), with F IS values ranging from 0.082 to 0.282. The mean F ST showed that approximately 96.5% of the genetic variation was within-population and 3.5% was among populations. Standard genetic distances were used to classify the ¢ve populations into two major groups. The deeper lotic river Nile populations of Assuit and Cairo formed one group and the shallow less lotic Delta lakes populations of Manzalla and Burullus formed the second group, with the upstream Nile Qena population being an outgroup. The ¢ndings from the current study help understanding of the broad-scale population structuring of the Nile tilapia (O. niloticus) allowing the population groupings identi¢ed to act as potential sources of genetic variation. These populations could be included in future Marker-Assisted-Selection programs for economically desired production traits.