The capacity of Pleurotus ostreatus to degrade the lignocellulose of spent coffee grounds (SCG) and its resultant nutrient composition is not yet studied. The study tested four SCG/wheat straw mixtures, containing 0, 33, 67, or 100% SCG. Initial lignin content was higher, and lignin loss was lower in mixtures containing SCG, compared to control revealing lower substrate degradation. Biological yield was negatively correlated with initial lignin content, and positively with the lignin loss from substrates. The nutritional value of mushrooms was improved by a general increase in carbohydrates, a decrease in sodium content with 33% and 67% SCG, and lower fat content with 33% SCG. Polyunsaturated fatty acids of mushrooms (PUFA) increased with 67% SCG; while saturated ones (SFA) increased with 33 and 67% SCG. All mushrooms had a close PUFA/SFA, ranging between 7.4 and 8.1. The study suggests using SCG as a nutritional supplement to the commercial wheat straw. Graphical abstract

Various abiotic stresses affect growth and development of plants and two important cues that cause to sever decrease the horticultural and crops yield are the heat and chilling stresses worldwide. Plants have various mechanisms to tolerate or avoid the stresses; one of these mechanisms is the biosynthesis of organic solutes. In this paper, effects of chilling (0-15 °C) stress on the horticultural (ornamental and vegetable) plants and crops are discussed. You will see that plants how to tolerate the stress by organic solutes. The most important organic molecules to regulate water relations in plants are introduced. The organic solutes that also are called osmo-protectants include soluble carbohydrates, amino acids and nitrogen compounds.

Various abiotic stresses affect growth and development of plants and one of them that causes severely decreasing the horticultural and crop yields is the heat stress worldwide. In this paper, the effects of heat (more than 30-35 °C in different species) stress on the horticultural plants and crops, and its effects on inducing other stresses, including osmotic and oxidative stresses are discussed. Plants show the molecular and biochemical responses after receiving environmental signals such as high temperatures and tolerate undesirable conditions.

Among major constraints to crop production, salt stress affects the morphological structure and yield in crop plants. Nano-fertilizers, have made their hierarchy to supplement the traditional fertilizers in mitigating the effect of abiotic stress due to their slow release and efficiency. Three products were tested namely lithovit®-standard(LITHO), monopotassium-phosphate(MKP:0-52-34), and aspirin(ASP) on salt-stressed tomato crop. These products were applied through foliar spraying (foliar) or fertigation (ferti) on tomato plants irrigated with 4 saline solutions (4, 6, 8 and 10dS/m). Control plants were subjected to five salinity levels (0, 4, 6, 8 and 10dS/m) without any treatments. Results showed that increasing in salinity levels adversely affected all parameters in the control plants. The ameliorating effect of MKP-ferti was prominent in plant height, stem diameter, number of fruits, fruit weight and yield/plant at 4 and 6S/m. Whereas, the effect of salinity was mitigated by LITHO-foliar regarding flowers number and total chlorophyll content at all salinity level. Leaf N, P and K contents were accumulated higher when MKP-ferti was used whereas, Ca²⁺ and Mg²⁺ contents were accumulated higher in the plants treated with LITHO-foliar. The cellular leakage of electrolyte was reduced at 4, 6 and 10dS/m with MKP-ferti and at 8dS/m with LITHO-foliar application. Among the two methods of application, foliar spraying of LITHO and ASP, and fertigation of MKP improved plant performance more than their complementary methods of application. The better performance of MKP necessitates the use of phosphorous and potassium-based nano-fertilizers. It can reduce the production cost of vegetables using conventional fertilizers.

The short shelf-life of mushrooms, due to water loss and microbial spoilage, is the main constraint for commercialization and consumption. The effect of substrate type combined with different temperatures and packaging conditions on the shelf-life of fresh Pleurotus ostreatus is scantily researched. The current study investigated the shelf-life of fresh oyster mushrooms grown on low (0.3, 0.3, 0.17) and high (0.7, 0.7, 0.33) rates of olive pruning residues (OLPR), spent coffee grounds (SCG), and both combined residues (OLPR/SCG) with wheat straw (WS), respectively, at ambient (20 °C) and 4 °C temperatures under no packaging, polyethylene plastic bag packaging (PBP), and polypropylene vacuum bag packaging (VBP). Results showed that at ambient temperature OLPR/SCG mushrooms PBP-bagged had an increased shelf-life by 0.5–1.2 days in comparison with WS ones. The predictive models adopted to optimize mushroom shelf-life at ambient temperature set rates of 0.289 and 0.303 of OLPR and OLPR/SCG, respectively, and PBP as the most suitable conditions (9.18 and 9.14 days, respectively). At 4 °C, OLPR/SCG mushrooms VBP-bagged had a longer shelf-life of 2.6–4.4 days compared to WS ones. Predictive models noted a maximized shelf-life of VBP-bagged mushrooms (26.26 days) when a rate of 0.22 OLPR/SCG is incorporated into the initial substrate. The combination of OLPR and SCG increased the shelf-life of fresh Pleurotus ostreatus by decreasing the total microbial count (TMC) while delaying weight loss and veil opening, and maintaining carbohydrate content, good firmness, and considerable protein, in comparison with WS regardless the storage temperature and packaging type.

Experimental research has been focusing on developing new substrates for growing shiitake mushrooms as alternatives to the standard oak sawdust substrate. The selection of appropriate lignocellulosic materials is based on their availability in the production area and their compatibility with the requirements of the mushroom species being cultivated. In comparison to oak sawdust substrate (OS) as the control, this study evaluated the potential of oak acorns (OA), olive pruning (OLPR), and vineyard pruning (VIP), and various combinations: OA-OLPR:1-1, OA-VIP:1-1, OS-OLPR:1-1, and OS-VIP:1-1, prepared on a dry weight basis. In comparison to OS, complete mycelial development was hastened in OA, OA-VIP: 1-1, and OS-VIP:1-1 by 9.5, 7.9, and 4.2 days and delayed in OLPR and OS-OLPR:1-1 by 11.3 and 7.0 days, respectively. Also, harvest was earlier in OA, OA-VIP:1-1, and OS-VIP:1-1 by 9.3, 6.7, and 3.3 days, respectively, while it was significantly delayed in OLPR, VIP, and OS-OLPR:1-1 by 12.3, 3.7, and 8.0 days, respectively. While the total biological yield was significantly reduced in OLPR, OS-OLPR:1-1, VIP, and OS-VIP:1-1, it was comparable to OS in OA, OA-OLPR:1-1, and OA-VIP:1-1 (597.0, 552.0, 532.2, and 556.2 g/kg, respectively). Production was consistently high over two consecutive flushes in OS, OA, and OA-VIP: 1-1. Total biological yields were higher in OA-OLPR: 1-1 than OS-OLPR:1-1 and in OA-VIP:1-1 than OS-VIP:1-1. OA increased mushroom number and firmness, VIP and OLPR increased mushroom weight, and OA-VIP:1-1 increased pileus thickness. Mushrooms' protein and fiber contents were higher than OS in all substrates and the highest in OA-OLPR:1-1 (8.7 %) and OLPR (2.8 %), respectively. Conclusively, the substrates OA, OA-VIP: 1-1, and OA-OLPR:1-1 may alternate oak sawdust; however, the first two substrates have an advantage over the third due to earlier harvests. Also, it is more favorable to use VIP and OLPR in combination with OA than to use them alone.