Nutrients consumed during the adult stage are a key factor affecting the growth, development, and reproduction of insect offspring and thus could play an important role in insect population research. However, there is absence of conclusive evidence regarding the direct effects of parental (F₀) nutritional status on offspring (F₁) fitness in insects. Carposina sasakii Matsumura is a serious, widespread fruit-boring pest that negatively impacts orchards and the agricultural economy across East Asia. In this study, life history data of F₁ directly descended from F₀ C. sasakii fed with seven different nutrients (water as control, 5 g·L⁻¹ honey solution, 10 g·L⁻¹ honey solution, 5 g·L⁻¹ sucrose solution, 10 g·L⁻¹ sucrose solution, 15 g·L⁻¹ sucrose solution, and 20 g·L⁻¹ sucrose solution) were collected under laboratory conditions. The growth and development indices, age-stage specific survival rate, age-stage specific fecundity, age-stage specific life expectancy, age-stage specific reproductive value, and population parameters of these offspring were analyzed according to the age-stage, two-sex life table theory. The results showed that the nutritional status of F₀ differentially affects the growth, development, and reproduction of F₁. The F₁ offspring of F₀ adult C. sasakii fed with 10 g·L⁻¹ sucrose had significantly higher life table parameters than those of other treatments (intrinsic rate of increase, r = 0.0615 ± 0.0076; finite rate of increase, λ = 1.0634 ± 0.0081; net reproductive rate, R₀ = 12.61 ± 3.57); thus, 10 g·L⁻¹ sucrose was more suitable for raising C. sasakii in the laboratory than other treatments. This study not only provides clear evidence for the implications of altering F₀ nutritional conditions on the fitness of F₁ in insects, but also lays the foundation for the implementation of feeding technologies within the context of a well-conceived laboratory rearing strategy for C. sasakii.

Bovine chymosin is key for cheese production, yet its traditional sourcing is unsustainable. While microbial and plant-based alternatives exist, they often cause non-specific proteolysis, leading to bitter flavors in cheese. This study aims to develop a high-yield, methanol-independent platform for recombinant bovine chymosin production by engineering the expression system of Komagataella phaffii through multi-factorial optimization. Initially, the native bovine prochymosin gene (pcw) was codon-optimized (pcm14) and cloned, along with an mCherry-tag construct (clpcm14), into inducible vector pPIC9 for expression in Komagataella phaffii GS115. Screening identified the fusion-tagged strain clp2-91 as the highest producer. Subsequently, the inducible AOX1 promoter in the previously selected clp2-91 strain was replaced with a constitutive GAP promoter, yielding engineered strain GH1. Cultivated in a 3L fermenter, GH1 exhibited a volumetric productivity of 105.03 SU/(mL·h), twice that of inducible strain clp2-91 (53.59 SU/(mL·h)). The further optimization of fermentation conditions (pH 4.0, glucose as carbon source, fed-batch mode) boosted the enzyme activity of GH1 to 12,000 SU/mL. The recombinant chymosin exhibited enzymatic properties similar to those of the native enzyme and, importantly, demonstrated a broader pH stability (pH 2.0–6.0). This study demonstrates an efficient strategy for chymosin expression in K. phaffii, offering insights that may support the future development and optimization of heterologous protein production in this yeast.